Switchable Graphics - Meet the Contenders

Before we get to the actual meat of this review, we have a disclaimer to make: both laptops we’re comparing came to us via NVIDIA. Now, before anyone cries “foul!”, let me explain. First, we asked AMD for just such a laptop back in May, and they haven’t been able to get us one yet (though it’s likely as much the fault of OEMs as AMD). We also only just received our first Sony laptop (from Sony) in a long while, and we received the VAIO C from NVIDIA first. Finally, the laptops came boxed up, unopened, with all the standard fluff you’d expect from retail notebooks.

After unboxing, we did our usual thing: create a new user account, and then commence uninstalling the bloatware—and yes, the Sony VAIO C and Acer TimelineX 3830TG both have a lot of it!—and when all that is done and we’ve shut off any unnecessary applications and utilities, we start installing our benchmark suite. After that’s done, we do a full defrag (using Defraggler) and then we can start testing. Despite the source of the laptops, then, we are confident that both are reasonable representations of what you’ll get—actually, the TimelineX 3830TG has some issues with throttling in games, so if anything NVIDIA’s choice for their own platform wasn’t the best, though the Sony VAIO C may not be the greatest AMD offering either.

In terms of other alternatives, while there are dozens of currently shipping Optimus laptops (ASUS, Clevo, Dell, HP, MSI, Samsung, Sony, Toshiba, and others are all onboard with the platform), finding laptops with Intel CPUs and AMD dynamic switchable graphics is a lot more difficult. Sony has the VAIO C—the VAIO S we recently reviewed doesn’t support dynamic switching, instead using the older manual switching—Dell has the Vostro 3450/3550, and HP has it with certain dv6/dv7 series laptops using 6700M GPUs. Meanwhile, 6300M (rebadged 5400M), 6500M (rebadged 5600/5700M) and 6800M (rebadged 5800M) can't support dynamic switching, and no one is trying to do it on 6900M. (Note: I’ve looked around for more details on which laptops support AMD’s Dynamic Switchable Graphics and came up empty, but if anyone can find a comprehensive list I’ll be happy to post it.) There may be a few other laptops out there with Intel CPUs and AMD 6000M GPUs, but there definitely aren’t as many options.

We’ll be running a few benchmarks later, so while we’re on the subject of laptops, let’s go over the full specs. Starting with the AMD Sony VAIO CA laptop, here’s what we have:

The OEM-only i5-2410M is a good entry-level Sandy Bridge processor, and pricing is only slightly higher than the base model i3-2310M (which is clocked at 2.1GHz and lacks Turbo Boost support). 4GB RAM is fine, and the HD 6630M is actually a fairly potent mobile GPU as we’ll see in a moment. The big problems with the VAIO CA are that it comes with a slow and rather outdated 320GB 5400RPM hard drive (Western Digital Blue) and it also has a ton of bloatware. The bloatware can be uninstalled, and we did that as our first priority, but the hard drive tended to be an ongoing concern. AMD’s Catalyst Control Center for instance pops up in a couple seconds on my desktop (Bloomfield + SSD + HD 6950), but on the VAIO C there are times when it can take upwards of 30 seconds (with the HDD activity light a solid orange). Games also tended to take a bit longer to load than we’re used to. Outside of those two areas, the VAIO C is pretty much standard consumer laptop fare: glossy 1366x768 LCD, decent but not exceptional build quality, and average speakers. The keyboard is decent, though I’d still prefer dedicated document navigation keys (rather than the Fn+cursor combinations Sony uses), and it does have nice backlighting.

On the other side of the table is Acer’s TimelineX 3830TG-6431, priced over $200 cheaper than the Sony. Acer has a habit of releasing laptops and then discontinuing them not long after, only to replace them with slightly different models, so we can’t guarantee the 3830TG-6431 will always be in stock; however, it appears readily available right now. The AS3830TG-6431 has on serious problem, unfortunately: the CPU tends to throttle down to 1.2GHz when gaming as the CPU and GPU end up creating more heat than the system cooling can handle. That’s a real shame, as if it weren’t for the throttling there would be a lot to like with the 3830TG.

For one, the floating island keyboard I detest so much on other Acer/Gateway laptops is gone, replaced by a chiclet-style keyboard. There’s a bit of flex but I can live with it, and the layout is good (except for the crazy backslash-joined-to-the-enter-key weirdness). This is also a very thin and light laptop, helped by the absence of an optical drive, and the dimensions would be very impressive given the i5-2410M CPU and GT 540M GPU if it weren’t for the thermal throttling problem. Acer gives the TimelineX an aluminum cover and palm rest as well, but the LCD is one of the worst I’ve used (poor viewing angles and weak colors, plus our sample has a red pixel in the middle center of the LCD that’s stuck).

Because of the throttling issue, the 3830TG benchmarks aren’t the best representative of what you can get from NVIDIA’s GT 540M. We’ll include two other laptops with the GT 540M (and Optimus) in most of our benchmarks as alternative reference points: the Alienware M11x R3 (i7-2617M CPU) and the Dell XPS 15 L502x (i7-2630QM). In theory, the i5-2410M should sit somewhere in between these two in terms of performance, but the throttling drops it lower in most tests. However, if you’re willing to play around with a utility like ThrottleStop, you can actually get the CPU to run at a constant 2.1GHz without any throttling (basically using the i5-2410M as an i3-2310M CPU). We tested with ThrottleStop set at 2.1GHz along with running “stock” (e.g. with throttling) to provide a couple more points of reference in our gaming results.

How AMD’s Dynamic Switchable Graphics Works

One of the things we discussed with AMD was the technical details of their dynamic switchable graphics. At a high level, things might appear similar to NVIDIA’s Optimus, but dig a little deeper and you start to find differences. To recap how switchable graphics works, let’s start at the top.

The original switchable graphics technologies used the IGP and dedicated GPU as discrete devices. Both were connected to the necessary display outputs, with some hardware muxes that could select the active device. This requires more cost in the motherboard, and switching results in a blanking of the display as one device is deactivated and the other comes online. In the earliest implementations, you had to reboot when switching, and the system would start with either the IGP or dGPU active. Later implementations moved to software controlled muxes and dynamic switching, which required Windows Vista to work properly (since the IGP driver would unload, the GPU driver would start, and then the display content would activate on the GPU).

NVIDIA’s Optimus changes things quite a bit, as there are no longer any muxes. The display ports are always linked to the IGP output, and NVIDIA’s drivers simply look for calls to applications that the dedicated GPU can help accelerate. When they detect such an application—and the user can add their own custom apps—the drivers wake up the GPU and send it the rendering commands. The GPU does all of the necessary work, and then the result is copied directly into the IGP framebuffer, omitting any flickering or other undesirable effects as the IGP is constantly connected to the display output. The GPU can wake up in a fraction of a second, and when it’s no longer needed it will power down completely. NVIDIA even demonstrated this by removing the dGPU from a test system while it was powered on. The only catch is that the drivers need to have some knowledge of the applications/games in order to know when to use the GPU.

The details of AMD’s Dynamic Switchable Graphics are similar in practice to Optimus, but with a few differences. First, AMD always has both the IGP and GPU driver loaded, with a proxy driver funneling commands to the appropriate GPU. Where NVIDIA is able to completely power off the GPU under Optimus, AMD has modified their GPUs so that the PCI-E bus is isolated from the rest of the chip. Now when the GPU isn’t needed, everything powers down except for that PCI-E connection, so Windows doesn’t try to load/unload the GPU driver. The PCI-E link state gets retained, and a small amount (around 50mW) is needed to keep the PCI-E state active, but as far as Windows knows the GPU is still ready and waiting for input. AMD also informed us that their new GPUs use link adapter mode instead of multi adapter mode, and that this plays a role in their dynamic switchable graphics, but we didn’t receive any additional details on this subject.

As far as getting content from the dGPU to the display, the IGP always maintains a connection to the display ports, and it appears AMD’s drivers copy data over the PCI-E bus to the IGP framebuffer, similar to Optimus. Where things get interesting is that there are no muxes in AMD’s dynamic switchable graphics implementations, but there is still an option to fall back to manual switching. For this mode, AMD is able to use the display output ports of the Intel IGP, so their GPU doesn’t need separate output ports (e.g. with muxes). With the VAIO C, both dynamic and manual switching are supported, and you can set the mode as appropriate. Here are some static shots of the relevant AMD Catalyst Control Center screens.

In terms of the drivers, right now you get a single large driver package that includes a proxy driver, an Intel IGP driver, and AMD’s GPU driver all rolled into one. Long-term, AMD says they have plans to make their GPU driver fully independent from Intel’s IGP driver. They say this will only require some packaging updates and that they should make this change some time in 2012, but for now they continue to offer a monolithic driver package. OEMs apparently get this driver on a monthly basis (or can at least request it), but it’s up to the OEMs to validate the driver for their platform and release it to the public.

In the case of non-switchable graphics, AMD has a monthly driver update that we refer to as “reference drivers” that is publicly available. At present, you download a utility that will check your laptop GPU ID to see if the laptop is officially supported by the reference driver. Right now certain OEMs like to maintain control of the drivers so the AMD utility will refuse to download the full driver suite. In such cases, users have to wait for the manufacturers to roll out updates (Sony, Toshiba, and Panasonic all fall into this category). In the past, we have been able to download the reference driver using a “sanctioned” laptop (e.g. something from Acer), and we were able to install the reference driver on a non-sanctioned laptop. However, this does not work with switchable graphics laptops; you need the monolithic driver package for such systems.

That takes care of the high-level overview of how AMD’s Dynamic Switchable Graphics works, as well as a few other related items. The details are a little light, but that at least gives us an introduction to AMD’s current switchable graphics solutions. With the hardware and software discussions out of the way, let’s turn to our gaming results first and see how the two solutions and GPUs compare in performance as well as compatibility.

Medium Detail Gaming Comparison

We’re going to focus on the main gaming target for this level of hardware: our Medium presets. The Low preset tends to look pretty lousy in several of the games (StarCraft II being the worst), while our High settings are too much for the GT 540M/HD 6630M in about half of the titles, even at 1366x768. Medium detail on the other hand should give us 30+ FPS in nearly all of the games we’re testing while still providing decent visuals. Here are the results.

In terms of performance, the 6630M matches up nicely against the GT 540M. It wins a few games by a small margin, loses a few by a similarly small margin, and ties in the remainder. If we were just looking at gaming performance, there’s not much to discuss here. NVIDIA still has CUDA and PhysX, and AMD has their Accelerated Parallel Processing SDK, but given the level of performance we’re talking about, you won’t need or use these extras most of the time. Unfortunately for AMD, it’s not just about gaming performance.

We tested ten games (though we don’t have results from the Alienware M11x R3 in Civilization V and Total War: Shogun 2), and the newest titles are Civ5 (13 months old) and TWS2 (6 months old). You’d hope that with relatively known games, compatibility wouldn’t be an issue, but we ran into two problems during testing.

The first wasn’t a consistent problem, but we did have a couple of crash to desktop issues when benchmarking DiRT 2 using Dynamic Switchable Graphics mode. The other issue was a lot worse, and it was in StarCraft II when running at anything more than the Low default settings. As noted earlier, SC2 looks pretty lousy at its minimum settings, and Medium detail (and possibly even High) should be more than playable on the HD 6630M. In dynamic mode, however, not only was performance quite a bit lower than expected at our Low settings, but at Medium and above there were tons of missing textures. The solution is to switch to manually controlled switching, which solved both the performance and rendering errors, but then why even have dynamic switching in the first place?

While we’re on the subject, let’s also take a look at a few other comparisons. Running “stock” on the CPU, the Acer 3830TG is slightly slower overall than when using ThrottleStop to limit the CPU to 2.1GHz. With ThrottleStop, the average score across ten games improves by 20%, so the CPU throttling has a major impact in games. Civ5, ME2, and TWS2 show the least difference, with Mass Effect 2 being the only game that ran slightly faster at the stock CPU settings; Mafia 2 runs 10% faster, Metro 2033 and STALKRE are 13% faster, L4D2 jumps up 28%, DiRT2 is 49% faster, and the ever-CPU-limited StarCraft II runs 58% faster. Interesting to point out is that 2.1GHz is 75% higher than 1.2GHz, so on average it looks like the 3830TG runs around 1.3GHz in StarCraft II.

Flipping over to the other GT 540M equipped laptops and using the best result from the Acer 3830TG, the Alienware M11x R3 averages out to 3.5% faster, but it only has a clear lead in two games (DiRT2 and SC2) while it’s slightly slower in L4D2 and Mafia2. The Dell XPS 15 comes in 9% faster than the 3830TG on average, with the biggest lead again coming from SC2; Mafia2 once again gives the 3830TG a lead, so the latest NVIDIA drivers appear to be playing a role.

Finally, since we now have results from the HD 6630M with a Llano A8-3500M as well as the i5-2410M, we thought it would be interesting to see just how much performance you give up by gaming with the slower Llano CPU. If you’ll recall, in our first look at a Llano notebook, we expressed concern that the CPU would hold back GPU performance. Out of our ten tested titles, only Mass Effect 2 ran faster on Llano with a dGPU. Most games (at Medium settings where the GPU becomes more of a bottleneck) are close: BFBC2 and Civ5 are exactly the same performance, Mafia 2 is 2% faster with the Intel CPU, and Dirt2, L4D2, Metro, and STALKER are all within 5-10%. Not surprisingly, StarCraft II is the big outlier, running over twice as fast on the Intel i5-2410M. We’re still not looking at similar driver builds, as the Llano laptop is running a Catalyst 11.6 derivative (8.862.110607a-120249E) compared to 11.1 on the Sony, but even so the average performance increase with an Intel CPU comes in at 12% (mostly thanks to SC2).

Since there were two games where we didn’t have a perfect experience, we decided to look at some more recent titles.

What about Recent Games?

We do have one major concern with AMD’s Dynamic Switchable Graphics that we haven’t really addressed so far: drivers. Why are drivers a problem? Just like AMD’s non-dynamic switchable graphics, you’re stuck waiting for your laptop OEM to release new drivers, as AMD’s mobile reference drivers are only for discrete GPUs (and even then, not all OEMs participate, Sony and Toshiba being two prime examples). The drivers for switchable graphics consist of a proxy driver that intercepts calls and determines which GPU should receive the request, Intel’s IGP driver, and AMD’s GPU driver. AMD informed us that they make a new driver build available on a monthly basis for switchable graphics, but it’s up to the laptop vendors to test and validate the driver (and add in their hooks for keyboard shortcuts like LCD brightness and such) and make it available to the public. Generally speaking, this happens when a laptop is first launched, and if you’re lucky, you might get one or two more driver updates before the OEM stops worrying about an older model laptop.

So how big of a concern is this really? Our selection of gaming benchmarks consists of games that are all six months to more than a year old, so any moderately recent driver should work properly on our test suite. As we’ve already noted, there was a periodic stability issue in DiRT 2 (not consistently reproducible and perhaps related more to the game than AMD’s drivers), and there was a major rendering issue in StarCraft II at medium detail settings or higher. With our current gaming suite experiencing problems, we wanted to look at some newer titles to see if the drivers might have additional issues.

We selected six games that have all come out in the past six months. In alphabetical order, the games are Deus Ex: Human Revolution, DiRT 3, Duke Nukem Forever, Portal 2, Super Street Fighter IV: Arcade Edition, and The Witcher 2—and we’re also tossing in results from Enemy Territory: Quake Wars just for fun (an OpenGL game). Some of these games will become part of our new benchmark suite in a couple months (after Battlefield 3, Rage, and Skyrim launch) while others are recent releases that ought to be moderately demanding. We did run performance tests on all of these games, along with testing for compatibility with the Sony and Acer laptops. First, let’s look at performance, using Medium settings.

So here’s where things get interesting. In our current (soon to be deprecated) list of games on the previous page, the 6630M in the VAIO C generally equals the GT 540M in the Acer 3830TG. NVIDIA wins in Bad Company 2, Left 4 Dead 2, Mafia II, Mass Effect 2, and STALKER: Call of Pripyat by 4-14%; AMD counters by claiming wins in Civilization V (3%), DiRT 2 (1%), Metro 2033 (6%), StarCraft II (31%), and Total War: Shogun 2 (6%). Obviously, StarCraft II is the big difference, and it looks like the CPU throttling (or using ThrottleStop to set the CPU speed to 2.1GHz) accounts for a large portion of the difference. As we mentioned on the previous page, the Alienware M11x R3 averages out to 3.5% faster than the best the Acer can muster, and the Dell XPS 15 comes in 9% faster than the 3830TG, so if the CPU throttling weren’t present we’d expect the 3830TG to end up around 6% faster than the VAIO CA. Be that as it may, let’s just call it a tie between the GT 540M and HD 6630M and move on to our newer titles.

Looking at the recent releases (along with the OpenGL Enemy Territory: Quake Wars), the tables shift dramatically. The closest the VAIO C/HD 6630M gets is in The Witcher 2, where the Acer 3830TG/GT 540M still has an 8% lead. Elsewhere, NVIDIA leads by over 50% in Deus Ex: Human Revolution, Duke Nukem Forever, and Super Street Fighter IV: Arcade Edition. Rounding things out, DiRT 3 is 28% faster, ETQW is a 20% lead, and Portal 2 is 15% faster. Also worth pointing out is that three of the games in this list (DiRT 3, Deus Ex, and Portal 2) are promoted by AMD (and SSF4 is promoted by NVIDIA). Overall, in our recent titles the Acer leads the Sony by a not-insignificant 35% on average—and that’s with an Optimus laptop that we’re either running at a slower CPU speed, or potentially getting some CPU throttling. How much of the performance loss is caused by unoptimized drivers is unclear, but we suspect the 6630M with Catalyst 11.8 would fare a lot better.

AMD Compatibility with Recent Titles

Along with performance, we also need to discuss compatibility for the recent releases. In something of a surprise, considering the AMD driver date and the release dates of the various games, we actually managed to run all of the games without major issues on both laptops. However, application based switching didn’t always work for AMD, requiring us to use manual switching in a few instances. There was also at least one instance where manual switching had problems, requiring us to use dynamic switching. We’ll have a video and additional discussion of our concerns with the AMD UI and switchable graphics implementation on the next page, but here’s how the games stack up in terms of compatibility for both AMD and NVIDIA.

In the “works as expected” category, Duke Nukem Forever, Portal 2, and The Witcher 2 all ran without any noteworthy issues. Deus Ex: Human Revolution also ran fine, but there was no way to use application-based switching and have it run on the Intel IGP (no loss, really). The same problem occurred with DiRT 3, but with a few extra glitches. First, there was a black border on the right side of the screen—approximately 80 or so pixels wide—that shouldn’t be there; it was present regardless of resolution and even in windowed mode. Second, in manual switching mode DiRT 3 did not render properly in full screen viewing, but worked in a window. Running in a window is not a good solution, so this is a pretty serious glitch. Super Street Fighter IV: Arcade Edition on the other hand ran fine on the IGP in dynamic mode, but on the dGPU the models wouldn’t animate properly and in general the game was unplayable. The workaround is to use manual switching (which may or may not be supported on all laptops—Sony’s VAIO C supports it, and HP added the fixed function switching option in an updated BIOS for the dv6/dv7 laptops), after which the game runs properly. Also worth noting is that a few titles appear to run somewhat faster in manual switching mode, SSF4 and SC2 being two examples.

Besides the above six “new” titles, it’s important to note that all OpenGL titles are currently unsupported by dynamic switching (e.g. Enemy Territory: Quake Wars, Minecraft, presumably Rage when it launches, and as far as we know all other OpenGL apps/games). The workaround is to use fixed function (manual) switching, similar to what we had to do for Street Fighter IV—which means you’ll want to make sure your laptop supports manual switching in some form. AMD informs us that they have a working solution for OpenGL dynamic switching, but it isn’t fully tested yet. It should come out in an updated driver, hopefully before the end of this year (*cough* Rage *cough*). Then we’ll need to see Sony and HP (and anyone else using AMD switchable graphics) to release their own updated driver, and this feels like more of a question of “if” rather than “when”.

NVIDIA Compatibility and Thoughts

All of our discussions so far have centered on AMD’s Dynamic Switchable Graphics implementation and any problems we encountered. What about NVIDIA’s Optimus Technology? First, we immediately note that NVIDIA is at an advantage here, since the 280.26 WHQL drivers we used are only a month old (and there’s a new 285.27 beta driver from last week available now). While our testing is by no means fully comprehensive, so far the only issue we encountered out of the 16+ tested games is in Total War: Shogun 2. The game runs fine, but we are unable to select the Very High preset. Our best guess is that the game is querying the Intel IGP/drivers and limiting a few settings based on the detected capabilities. (We saw a similar issue in the older Empire: Total War in the past, except the last we checked it was limited to the Medium preset.) For someone with a high-end laptop (e.g. GTX 580M), the Very High settings might be desirable, but for 99% of laptops you’ll need to run at High or even Medium settings to get acceptable performance from Shogun 2. Overall, NVIDIA’s Optimus Technology is clearly the more mature and easier to use dynamic switching technology right now.

The only area I can come up with where Optimus isn’t desirable is if you want to run Linux, which isn’t high on NVIDIA’s list of priorities right now—in fact, they’ve said they’re not even going to bother trying to make Optimus work with Linux. This doesn’t make AMD’s switchable graphics solution superior in Linux, unless something has changed and the AMD drivers (or the open-source initiative for AMD GPUs) have improved since the last time we looked. I also have no idea whether AMD’s Dynamic Switchable Graphics works under Linux; it appears that AMD is doing some extra work in their drivers to make things run under Windows, so they might have the same issue as Optimus under Linux. I can’t say it really matters to me either way, as I don’t run Linux, but if you do feel free to add in your comments on which GPU vendor is better, and any information on how the switchable graphics solutions fare. My hunch is that a discrete-only NVIDIA GPU is still the way to go, and if you’re really into Linux the old-style manual switchable graphics with muxes is the better solution.

Summary of Compatibility

Our list of tested titles is obviously limited—I’m only one person, and even with a month of testing there’s only so much I can do—but so far we have yet to find a title that absolutely would not work on either the Sony or Acer laptops. For Acer (NVIDIA Optimus), nearly all games/applications worked without any extra fiddling, but you may need to manually add newer titles (or wait for NVIDIA to release a profile update). On Optimus, the only choice is to run in dynamic switching mode, but that’s generally fine because it works so well. On AMD, depending on the game you might need to select either dynamic switching or manual switching, and if you’re playing multiple games (or using some other GPU enabled application) you will very likely have to go back and forth during the course of a day of gaming. That may sound reasonable, but a lot of users want something that just works without a bunch of extra fussing around, and AMD is coming up short in that area. So, let’s go through changes and annoyances we’ve experienced in testing the Sony VAIO C, specifically as it relates to AMD’s switchable graphics.

Let’s Talk About Drivers

So what does our discussion of gaming compatibility and performance really mean? First, let’s start by looking at the AMD driver version. The CCC version used by Sony appears to date from February 4, 2011 (software version 8.811.1.5-110204a-115635C-Sony), so best-case we’re looking at bits and pieces from the Catalyst 11.2 era, but mostly 11.1. Ouch. There are also oddities with the Sony driver release where sometimes not all CCC options are available (e.g. the Information tab doesn't always show up). CCC also crashed a few times when switching between manual and dynamic modes (or IGP and GPU modes when in manual switching). Given how old the Sony drivers are, many of the lower-than-expected performance results (particularly in the recent titles list) should improve with something like the Catalyst 11.8 drivers. That right there is reason enough to consider bypassing any laptop where you can’t get up to date drivers from the GPU manufacturer, and Sony completely misses the boat with their AMD-equipped laptops.

For any consumer notebook with a discrete GPU, if the GPU is actually supposed to be useful over the long haul, owners need the ability to get regular driver updates. For games in particular, in some cases driver updates can mean the difference between running properly or not at all; in other instances, a new driver might increase performance by as much as 20% or more, especially on new releases. And lest anyone get the idea that I’m just picking on AMD’s mobile drivers, let me refer back to something I wrote in 2008 (and substitute “gaming” for “SLI”): “Honestly, what we really need is the ability to run reference drivers on gaming laptops - even more so than regular laptops, although that would also be great. As far as we're concerned, a gaming notebook needs to be as seamless as a desktop when it comes to updating drivers and running games. Until that happens, we would think very carefully before spending a lot of money on gaming laptop.”

I took NVIDIA to task for their lack of generic driver updates over three years ago, and over the next two years we saw the situation improve with their Verde program, Optimus Technology, and then the two combined so that virtually all NVIDIA-equipped laptops (a few business-centric laptops may not qualify) can get new drivers the same day that desktop drivers launch. Today it's time to give AMD and Sony the same treatment. For Sony, I really see no point in shipping a laptop with a discrete GPU and then doing nothing with the drivers; long-term, you might as well just sell the laptop with an Intel IGP rather than going after the checkbox feature.

AMD has a similar program to NVIDIA’s Verde, but notably absent from the program are the following: laptops with switchable graphics and Intel chipsets, Toshiba notebooks, Sony notebooks, and Panasonic notebooks. Thus, Sony gets a double fail on the driver situation with the VAIO C: once for not participating in AMD’s mobile driver program at all (for non-switchable laptops), and the second they get to share blame with AMD (for switchable graphics). Simply put, NVIDIA has the better approach: provide reference drivers for nearly all laptops that use NVIDIA GPUs, and include support for laptops with Optimus graphics switching technology. (Incidentally, if you look at the latest NVIDIA driver release notes, Hybrid Power laptops aren’t supported, since they use manual graphics switching technology similar to AMD’s switchable graphics, and only a couple Sony laptops are supported. Fujitsu laptops are also on the unsupported list.)

UI Concerns

I brought up my concerns with AMD in regards to their mobile drivers prior to writing this article. Their general stance is that they want to make things “easy” by not overwhelming users with too much information. For advanced users (like myself and many of our readers), they can fall back to the fixed function switchable graphics (i.e. manual mode). My major gripe is that making things easy apparently means not providing a global list of applications/games with profiles—something we’ve been asking them to add since CrossFire first hit the scene! Just to be clear, I strongly disagree with their “easy” suggestion, because using the VAIO C made it patently clear that this is not easier than using an Optimus-based laptop. Here’s why.

It’s true that you can switch between dynamic (application based) switching and manual switching, but as I’ve discussed earlier, there are instances for both sides where games don’t work quite right. The solution thus becomes one of opening the CCC, selecting the appropriate mode (there’s no quick way to tell which mode you’re in outside of the CCC), and then you can load the game. First, I have to say that opening AMD’s Catalyst Control Center and switching between dynamic and manual modes is hardly ideal—in fact, it can often be a bit of a pain. Particularly on this Sony laptop, I’ve noticed that the CCC frequently takes far too long to load—I’ve seen it take upwards of 30 seconds on a regular basis! A slow hard drive with a bloated .NET interface appears to be the issue, but whatever the cause (an old driver as well?), it can be annoying.

There’s also the question of what games are supposed to work properly, and there’s no global source you can consult for this information (at least, not that I could find). AMD can call it overwhelming if they want, but NVIDIA’s drivers make it really easy to see if a game at least should work with Optimus (though even unlisted games have worked in my experience so far). AMD’s application based switching looks for anything using DirectX calls as far as I can tell, which results in things like dialogs asking whether Explorer.exe should run on the Power Saving GPU or the High Performance GPU. Perhaps that’s a better definition of overwhelming: popping up dialogs that aren’t necessary? Early on in testing, I turned off the “prompt every time a new graphics application runs” option; if you want to get it back, however, you’ll need to restore the default settings as there’s no box to uncheck. Either way, the first time you launch a graphics-enabled application, it’s given a “Not Assigned” classification, which appears to be about 50-50 in terms of running on the IGP or running on the GPU.

In general, I found the manual switching mode to be the better AMD solution right now—only DiRT 3 had a major issue there. Contrast that with minor to major annoyances in Super Street Fighter IV: Arcade Edition, StarCraft II, and all OpenGL titles not working with the application-based switching and there’s really no point in dynamic switching. But then, we’re also looking at drivers from over seven months back, apparently, so perhaps things are better—we couldn’t check, as we don’t have another laptop with AMD’s switchable graphics and a more recent driver available. Even if you skip dynamic switching, manual switching isn’t a great experience either, since the screen will flash and go blank for 5-10 seconds every time you switch between the IGP and GPU. Granted, in most cases the only time you’d actually need to do that would be when going from AC power to battery power—get the switching to happen faster and get me regular driver updates and I’d be fine with manual control.

Other Requests

When I first laid hands on a laptop with switchable graphics, I predicted that such a design would become the future for mobile GPUs. Really, if everything works properly on a low-end or mid-range GPU, there’s no reason it shouldn’t work on high-end GPUs as well. Once that happens, there’s a good incentive for notebook manufactures to use graphics switching on every mobile product that has a dedicated GPU.

This is precisely what we’ve seen with NVIDIA’s mobile lineup. Starting with the 200M, we saw only a couple laptops with Optimus or some other form of switchable graphics. The 300M is when Optimus really gained traction on virtually all the mainstream laptops, and with 400M we started to see higher performance mobile GPUs with Optimus support. Now their 500M even has a few vendors (e.g. Alienware M17x) that use Optimus on their top-end GTX 580M.

For AMD, right now it looks like the only laptops with dynamic switchable graphics use either the HD 6400M or the HD 6600M/6700M (same chip at different clocks). The HD 6470M is almost superfluous these days, considering Intel’s HD 3000 is within striking distance (and Ivy Bridge will apparently close the gap). Meanwhile, the 6300M, 6500M, and 6800M are just renamed 5400M/5600M/5800M chips, so they apparenlty lack the necessary hardware change to do dynamic switching. It's not clear whether 6900M can support dynamic switching, and high-end GPUs could certainly benefit (assuming the bugs and other issues are worked out), but no one is doing it. Perhaps it’s just a case of the chicken and the egg: if AMD gets dynamic switching to work properly on all their mobile GPUs, vendors would be a lot more likely to use the technology on high-end laptops.

With all my talk of switchable graphics, though, let’s make one thing clear: switchable graphics is not necessarily the Holy Grail of mobile GPUs. The true ideal in my opinion is mobile GPUs that can run fast when needed (i.e. playing games), while also being able to power off large portions of the chip and RAM and get down to IGP levels of power consumption. The GTX 580M for instance has 384 CUDA cores divided into eight Shader Modules, with a 256-bit memory controller divided into four 64-bit interfaces. When playing games or doing other intensive graphics/computational work, the GTX 580M can use up to 100W of power. At idle, we estimate power consumption to be around 16W, which obviously takes a toll on battery life.

Imagine if the GTX 580M could fully shut down seven of the eight SMs and three of the four memory interfaces, as well as doing some voltage and clock speed modifications. Do we need more than 48 CUDA cores and a 64-bit memory interface for the Windows desktop? Most likely not. It’s possible with the right design, we could get a dedicated GPU that would idle at less than 1W—similar to current IGPs. If we can get that, then there’s no actual need for graphics switching technology; you’d get the best of both worlds. But until and unless we reach that point, technologies like Optimus and dynamic switchable graphics are the next best thing—at least when everything works properly. Of course, with AMD’s APUs and Intel putting faster IGPs into their CPU packages, focusing on switchable graphics makes a lot of sense. Going forward, nearly every consumer CPU is going to have some form of on-die graphics, so why not put it to good use?

Video Demonstrations

With all of the discussion of problems and UI issues, I felt the inclusion of some videos showing exactly what I experienced were in order. If a picture is worth a thousand words, then an 11 minute video ought to speak volumes, right? I’ve already covered most of the material, but I put together two videos, one showing various games and UI interactions on the Sony VAIO C and the second demonstrating similar use of the Acer TimelineX 3830TG. The first and likely more interesting video shows the gaming experience on the Sony laptop.

[Note: I’m still working on the Acer video; it should go up some time today, but there’s not a lot to see—the games I tested all run as expected.]

Again, without a different laptop, we can’t say how many of our complaints are specific to the Sony VAIO C and how many apply to AMD’s Dynamic Switchable Graphics in general. There haven’t been any major UI changes to AMD’s Catalyst Control Center lately, but there are almost certainly some performance, compatibility, and stability changes. Take the above video as a demonstration of what the Sony VAIO C delivers, and hopefully we’ll be able to test a more recent AMD driver in the near future.

Closing Thoughts

This has been the first laptop with AMD switchable graphics that I’ve had a chance to actually review, and it hasn’t impressed me as much as I would like. I can’t say I’m really surprised, as I’ve been trying to get my hands on such a laptop since the HP Envy 14 launched. If it worked perfectly and could match NVIDIA’s Optimus, I imagine AMD and/or their partners would have been pushing it into reviewers’ hands a lot more. Regardless of delays in getting a test sample, we’ve finally had a chance to test AMD’s Dynamic Switchable Graphics and we can tell you where it stands…sort of. Let’s recap.

AMD’s dynamic switching is fine when it works, but in our testing it fails to work on a regular basis. Mostly, it just feels like it needs more development and testing; given sufficient resources and time all of the issues I’ve experienced on the VAIO C could get resolved. Long-term, AMD needs a lot more games to get explicit support; out of sixteen titles, not even counting OpenGL games, four of the games had some sort of problem with dynamic switching. On an NVIDIA Optimus laptop, every single game worked without any tweaking necessary. That’s what AMD needs to achieve at this point, and preferably do so without any performance compromises.

The bigger issue of course is that AMD needs to get their laptop partners—Sony in this case—to release regular driver updates, and to use up-to-date driver builds when laptops launch. For all we know many of the issues have been addressed in the months since the February build; instead, Sony has a driver released in June 2011, but with a version number that suggests it was already over four months old at the time the VAIO VPCCA290X launched. We found that the Llano A8-3500M with the HD 6630M outperformed the VAIO CA, which simply shouldn’t happen (unless AMD has some special optimization on Llano that allow their GPUs to run faster). It looks like Sony has given up at least 10% of the performance potential of HD 6630M on average, and in some games the outdated drivers may be culling a third of the performance potential.

That’s really my main concern if you haven’t noticed: drivers. If you have an AMD IGP and AMD GPU (e.g. Llano), some of this discussion becomes unnecessary. Since AMD provides both graphics drivers in that case, updates should be a lot easier, although OEMs would still need to sanction the reference drivers. If an OEM were willing to commit the resources necessary to at least do bi-monthly driver updates for switchable graphics, that would also be sufficient, but they’d need a proven track record of doing so—something no laptop manufacturer has ever achieved. Another alternative is for AMD to get the OEMs on board with letting AMD release reference drivers, including for switchable graphics platforms on Intel chipsets, but no one has managed to do that either and I don’t see things changing. As noted earlier, AMD already has plans in place to move to fully independent graphics drivers, hopefully some time in 2012, but best-case we’re four months away and worst-case it might not even happen in 2012.

That’s another part of the problem with AMD’s drivers, unfortunately: they currently have people working on Brazos, Llano, the upcoming Trinity, existing desktop and notebook graphics, the HD 7000 series, and switchable graphics (plus some other tidbits I missed I’m sure). I doubt that fixing their Dynamic Switchable Graphics drivers will take priority over getting HD 7000 and Trinity drivers ready, and AMD could probably use more people working on improved compiler support for Bulldozer while we’re at it. In other words, there are a lot of areas in AMD software development that need people, and how many people are working on Dynamic Switchable Graphics is unknown. NVIDIA’s Optimus Technology currently enjoys a healthy lead in dynamic switchable graphics and AMD is trying to play catch up, and I’m not sure they’re ready to commit the manpower required to make it happen. It’s hardly a surprise then that where more than 100 Optimus enabled laptops have launched in the past 18 months, there are only a few laptops with AMD’s Dynamic Switchable Graphics—and only a dozen or so laptops using any form of AMD switchable graphics to my knowledge.

To be fair, let me also point out that NVIDIA's Optimus Technology didn't launch and immediately work with everything. Taken from that perspective, AMD's Dynamic Switchable Graphics is about 18 months behind NVIDIA, and hopefully we'll see the technology mature and improve during the next year. We look forward to the day where the compatibility problems we experienced are largely addressed, and we can all get back to using our computers rather than wrestling with them. (Wake me when that happens!) AMD has the groundwork laid at least, so whether it takes six months or 18 months, at some point we should have the ability to get updated drivers for our AMD, Intel, and NVIDIA graphics solutions without worrying about breaking certain features. If that sounds like a pipe dream, just ask some of us old timers about the joys of DOS drivers, loading high, and EMM386.SYS.

As far as the VAIO CA goes, Sony makes a decent laptop—we’ll give it a separate review shortly. The VAIO CA isn’t at quite the same level in terms of build quality and materials as the VAIO SB Dustin reviewed, but it does provide reasonable performance and some of the best battery life results we’ve seen for the specs. If nothing else, Sony at least knows how to tune their laptops for long battery life. Pricing is where things get dicey; there are some $800 VAIO C models that have the same specs as the review unit, but it’s not clear if they include the HD 6630M or not—we’re guessing not. Going straight to Sony, you can configure the VPCCA290X with all the options of our review unit at a not-too-onerous price of $930. Where Sony completely fails however is in their driver support; shipping a laptop with discrete graphics using drivers that are at least four months old (at the time of launch) is tantamount to telling your customers that they don’t need the graphics card at all! But we say the same thing about HD 6470M and yet several companies (including Sony) are still using it.

Ironically, I’d rather have something like the HP Envy 14 or the Sony VAIO C without AMD’s switchable graphics and just give me a discrete GPU instead; that would make getting updated video drivers easier and battery life doesn’t even suffer all that much. AMD is actually a bit closer to my ideal of not needing switchable graphics than NVIDIA, as their mainstream GPUs tend to use less power. Their HD 6630M still draws about 2.0~2.3W more than Intel’s HD 3000 IGP under low loads and 2.8W more during H.264 decoding, but that compares to around 4.3W more for a GT 540M doing H.264 decoding. (We can’t test idle power draw since Optimus just shuts the dGPU off—not that that’s a bad thing.) Of course, the 6630M at ~8.3W idle is still using about 30% more total power than with the IGP (6.0W), but you can still get over six hours of battery life.

Given the price of $930 for the Sony VAIO C, at that point you’re within $150 of better built laptops with nice 1080p displays—e.g. the Dell XPS 15z, or wait for the XPS 14z to show up and see what it offers. If you don’t mind the CPU throttling (or at least running games while using ThrottleStop), you can also grab the Acer TimelineX 3830TG-6431 we used as a comparison point in this article for just $700. The MSI X460DX-008US for $727 (with i3-2310M and a 14” LCD), 15.6” Acer Aspire AS5750G-6496 for $680, or the 15.6” Gigabyte Q2532N-CF1 for $885 are also available for less money than the Sony—and that’s just naming a few of the Optimus laptops with Sandy Bridge CPUs and GeForce GT 540M GPUs. In short, you can get any laptop equipped with NVIDIA’s Optimus Technology and get the improved battery life that running off the IGP affords while still having readily available driver updates, frequently at a lower price. Unless you absolutely don’t care about driver updates—or a UI with lack of “expert” features like a list of game and application profiles and global settings—NVIDIA is definitely the way to go for dynamic switchable graphics technologies right now.

Just to wrap things up, obviously I’m just one person testing these things out, and we have a lot of readers. It’s also been frustrating trying to get a laptop with AMD Switchable Graphics in for testing, and while NVIDIA shipped us a Sony VAIO C, it’s possible that other laptops out there (HP dv6/dv7 and Envy 15/17) might have better driver support. Hopefully we’ll be able to get one (or more) of those for testing, at which time we can revisit this subject, but until then I’d love to hear your thoughts and input on switchable graphics as well as compatibility. What problems/glitches have you run into with Optimus that I might have missed? Outside of Linux non-support, are there any major issues with Optimus that you’d like addressed? The same goes for the AMD side: what other titles are having issues on any of the dynamic switchable graphics laptops? How have laptops with AMD switchable graphics fared in terms of driver updates over time? Does AMD’s switchable technology work any better under Linux that NVIDIA’s Optimus? If any of you can provide specific complaints/concerns with details of how to reproduce the problem(s) for either platform, please sound off in the comments section, or shoot me an email.