Bigfoot Networks has, for the past few years, been trying very hard to bring high powered, intelligent network interface cards to the desktop. We previously looked at their Killer NIC with some interesting results, and today we've got the Killer Xeno Pro in our labs.

The major difference between the older Killer NIC and the newer Killer Xeno Pro is the inclusion of an audio path and audio processing for voice chat acceleration. They Killer Xeno Pro also has twice the RAM of the original. Despite the improvements, one of the major benefits is that the Killer Xeno Pro will be available at a lower retail price than the Killer NIC was. Oh, and it is sort of cool to see the new hardware dialog talking about a PowerPC Processor:

I sooo want to hack this thing now.

In our original investigation, we did see some situations where the Killer NIC could make some difference, but, for what you get, the cost was much too high. One of the ways that Bigfoot is trying to combat this is by selling chipsets and letting vendors like EVGA build and market boards. They've managed to get their costs down and the price of the Killer Xeno Pro, while very high for a network card, is much more reasonable than the original offering. The EVGA Killer Xeno Pro can be had for about $120 USD.

The EVGA Killer Xeno Pro in all its glory.

Let's start by saying that this isn't going to be a network card for someone hanging on to a 7 Series NVIDIA card or a Radeon 1k part from ATI in a single core CPU system. When upgrading, spending the $120 cost of the Killer Xeno Pro on a better graphics card will net you a great deal more performance. Even putting that money into the CPU is likely to get you more for your money in general. This is a card that should be targeted at the online gamer with a good system who wants to make sure every possible advantage is covered.

This hardware at this price is just not for everyone. It still needs to come down to more of a commodity price in order to see wider adoption. In our opinion, those who should even consider this card should already have a modern dual core system with single GPU graphics hardware capable of delivering a good, steady, high framerate at the preferred resolution in the majority of games. We don't expect that everyone who has such a system will want to invest in the Killer Xeno Pro either, but let's not get too far ahead of ourselves.

Up first we will look at the Killer Xeno Pro, its features, and why we should expect some level of increased performance at all from a typical network card.

The Card and Features

This card sports a 400MHz PowerPC processor with 128MB of RAM, essentially making the Killer Xeno Pro a computer on a x1 PCIe board. As with the first generation, the major feature of the Killer Xeno Pro is it's ability to offload TCP/IP work from the CPU by bypassing the Windows TCP/IP stack.

Microsoft's built-in TCP/IP stack requires the CPU to handle network packet processing. Additionally, when packets arrive, they don't generate interrupts and applications must poll for data (which also wastes time and resources). Bigfoot Networks claims that the windows networking stack is not designed for low latency operation while the Killer Xeno Pro is. Regardless of how (or how efficiently) a software network stack is implemented, having it run in hardware will reduce overhead and impact on the rest of the system. It should also be noted that, for applications which require the windows networking stack (like some VPN products), the Killer Xeno Pro can disable it's "game mode" and enable "application mode" which does disable TCP/IP offload and can increase compatibility in some cases.

Adding to this, the Killer Xeno Pro hardware is capable of offloading other network centric tasks like VoIP, firewalls, and networked storage (though these features are not all fully supported with appropriate software at this point in time).

Installing the hardware is very straight forward, as it's just a simple PCIe card. If you want to use the voice chat features, the only additional need is to connect either the internal or external audio cable. No power is required, and other than that the network port is all that you'll need to worry about. Despite the fact that there is a USB port on the card, it is not used for anything at this point (but Bigfoot has indicated future potential to enable hardware managed USB attached storage).

Mic in and audio line out on a NIC; now that's a first.

The only installation issue we noted is that the driver install, when necessary, will also flash the Killer Xeno Pro hardware. There isn't very much warning about what's going to happen and no confirmation dialog before the start of the flash process. Those who click through install programs quickly without reading them might get themselves into a bit of trouble. There is no way to cancel the flash update once it's started, and while flashing hardware isn't as risky these days, it might be nice if the drivers were a little more clear about what was going to happen.

Easy mode switching.

The hardware comes with drivers and a tray application that are capable of bandwidth throttling and prioritization. Control can be down to a per application basis and maximum download and upload speeds can be specified. Or for benefit without the headache, applications can be prioritized allowing hardware and usage patterns to determine effective bandwidth. Unfortunately, the drivers and applications for the Killer Xeno Pro only run on Microsoft Windows operating systems (XP and Vista flavors). With the gaming focus, this makes sense, but it would still be nice for those who like to dualboot Mac OS X or Linux.

Per application QoS.

Per application bandwidth limits.

With software support, games and voice chat software can completely delegate any VoIP functionality to the Killer Xeno Pro which would handle taking input from the microphone (which plugs straight into the Killer Xeno Pro), compressing the data and sending it out over the network. When a voice packet is received by the Killer Xeno Pro, it decompresses it and sends it straight to the sound card (either via the soundcard's line-in port or an internal cable) bypassing the rest of the system completely. This should help reduce CPU overhead and voice lag caused by sources other than the network or server.

While this is great from a geeky technical standpoint, there isn't a huge amount of overhead on modern CPUs for voice chat software, and the network is by far the largest source of delay. So the actual benefit isn't going to be huge. These issues are the same with hardware firewall, bandwidth control, and all the extras.

The TCP/IP offload capability of the hardware will definitely remove another task from the CPU and operating system. This will free up resources that could be useful for other things, but the real world benefit of this will be very small in most games where the majority of the work is done on the GPU rather than the CPU. Having an NPU (network processing unit, as Bigfoot Networks likes to call it) that handles TCP/IP processing as soon as packets are received and uses hardware interrupts to let a game know that network packets have arrived (rather than requiring polling) can help decrease the latency between when a packet is received by the network card and when a game is able to make use of it, but as with the voice issue the largest delay is inherent in the internet itself and there is only so much benefit that can be had by optimizing the client side.

Not to say that optimizing client side networking is a bad thing: it certainly is not. The real question here is not whether the Killer Xeno Pro does something useful (because it does), the question is whether that useful thing has any significant impact on experience (and if that impact is high enough to justify the price).

Mostly Deterministic Testing

Designing tests to determine the real world benefit of the Killer Xeno Pro has proven quite difficult. Even though frame rate testing with single player games isn't strictly deterministic, proper tests can produce results that are fairly consistent and have low variance. We haven't included many MMOs or multiplayer games that don't utilize timedemo functionality in our graphics hardware tests specifically because they are very hard to appropriately benchmark. We can get ideas about performance from play testing, but graphs and charts have a certain finality and authority to them that we just don't want to lend to tests that we can't stand behind are representative of relative performance.

We did come up with one test that is highly reliable, however. This test is a side by side comparison of framerate when playing EVE online. We ran two different computers side by side with exactly the same hardware and software setup except that we installed the Killer Xeno Pro in one box. Both instances of EVE undocked characters in Jita (a system that typically hosts about 1000 players at a time) and flew to nearly the same spot. Because EVE allows players to choose something to "look at" and centers the camera on that object, were were able to have two instances of the game running with players very near each other (requiring very similar network data) and with exactly the same graphical load (because they were looking at the same thing).

Our EVE test is in a place where there were a very high number of other players and we were able to eliminate as many other factors as possible from testing. This test showed no difference in performance with or without the Killer Xeno Pro:

We attempted testing in other multiplayer environments like Team Fortress 2 and World of Warcraft, but we couldn't eliminate graphics as a factor when side by side testing with different players like we could in EVE. If we did sequential testing, one run to the next had very high variability even on the same hardware (due to the influence of other players).

We did run some tests in not very highly populated areas of WoW and found that framerate and ping seemed to show no difference. This might be different for highly populated areas, but again we couldn't be very deterministic in testing this.

In trying to do the similar testing with Team Fortress 2, the Killer Xeno Pro would be faster in once instance and slower in the next. There was no real consistency to our data in this case.

Bigfoot claims that there is benefit from the hardware in games like WoW, Team Fortress 2, Counter Strike: Source, and other games with high volumes of network traffic. We really do not doubt the capability of the hardware to provide some sort of difference, but our tests just are not deterministic enough to appropriately compare the hardware. But in a way this does tell us something very important: factors other than client side networking (like the performance of the network itself, other players, servers, and potentially graphics) have a much higher impact on performance.

The Killer Xeno Pro does suggest another advantage: bandwidth prioritization and throttling. The hardware is capable of Quality of Service (QoS) like prioritization on a per application basis, and every application can have upload and download bandwidth caps. This could potentially help out when multiple network heavy applications are vying for bandwidth. We decided to test this with both EVE (for framerate and download speed) and WoW (for framerate and latency).

In our EVE test, we used uTorrent to download a 650 MB file while we played EVE. Because we had to do this test sequentially rather than side by side (the bandwidth demand from on torrenting computer would negatively impact the bandwidth available to both PCs -- a point we'll come back to later), our frame rates aren't directly comparable because of all the other player activity. Please keep in mind that fluctuations in the multiplayer environment make this a non-deterministic test despite the fact that framerates are similar.

We did, however, see a very large difference in the time it took to download our torrent.

Since we can't get an assessment of ping times in EVE, we did some testing on WoW in the same unpopulated area. Normalized to the average latency we experienced while not downloading a torrent, here's the latency incurred by downloading a torrent:

Even with these latency differences, our framerates were very constant at about 54 FPS with 0.4% difference between the three different setups.

Again, this might have a larger impact in a more highly populated area in WoW. But the hardware does show a ping time advantage over our on-board NIC when downloading a torrent while gaming.

Experience Testing

Because we couldn't perform as many useful repeatable tests as we wanted, we have done quite a bit of just plain gaming. We played with the hardware and without the hardware. We tested EVE Online and Team Fortress 2. Bigfoot reports that Team Fortress 2 sees some of the highest benefit from their technology, and we included EVE in order to gauge impact on network games / MMOs that were not singled out by Bigfoot. We played around with WoW for a while, but we don't have a high enough character to do anything where latency could really matter (large parties playing end-game content). These tests were done the way we normally game: with nothing running in the background and no downloading going on.

In playing on our Core i7 965 system with an NVIDIA GeForce GTX 280 and 6GB of RAM, we spent a couple hours with each game. Half of our time was with onboard networking and the other half with the Killer Xeno Pro. Both games were run at their highest quality settings and resolution on our 30" panel.

In EVE we ran some missions and got into a little PvP action. While we made more isk (EVE's in-game currency) playing with the Killer Xeno Pro, this was just the result of the missions we were handed. Neither PvE nor PvP situations felt any different with the onboard NIC versus the Killer Xeno Pro. Action was just as smooth and the UI was just as responsive no matter what was going on. We felt the same sort of loading hiccups when changing areas with both networking solutions as well: the Killer Xeno Pro just didn't deliver any tangible benefit in EVE Online.

Our Team Fortress 2 testing consisted of lots of different games played on both the on-board NIC and the Killer Xeno Pro.

We do need to preface this by acknowledging the fact that none of us are really twitch shooter experts. Sure, we all played and loved Counter Strike and CS:S, Unreal Tournament in all its incarnations, and many other FPS games, but we aren't the kind of people who run moderate resolutions with 16-bit color and most of the options turned as low as possible in order to get every single possible advantage. We are also not professional gamers; but we do love to game.

That being said, we really didn't notice any difference in our gaming experience with or without the Killer Xeno Pro. I tend to like sniping in games, and typically even non-twitch gamers can tell if they're being screwed out of kills by network issues. I didn't experience this sort of frustration with either solution. Game play was smooth and not jerky or problematic even in larger fire fights when there were no other issues at play. When playing both with and without the Killer Xeno Pro, we experienced some issues when on servers with issues.

It is just a fact that the most important factor is going to be finding a game where you and all the other players have a low latency connection to the server. The slight difference of a minimally reduced client side latency is not going to have a higher impact than any sort of other network issues.

In other words (and to sum up), when you have a bad connection, the Killer Xeno Pro is not going to fix it; when you have a good connection, the Killer Xeno Pro is not going to make the experience any better.

Final Words

The approach and design of the Killer Xeno Pro are more efficient than standard network cards. Bypassing the windows networking stack will reduce load on the operating system and the CPU. Bypassing the CPU and OS when sending and receiving audio using supported voice chat software is a cool thing as well. Built in hardware prioritization (QoS) and bandwidth throttling are also interesting features.

But the bottom line is that none of this makes a significant difference in the gaming experience on modern PCs when paired with current games, nor does it offer an advantage over alternatives.

The biggest advantage the Killer Xeno Pro showed was in it's ability to prioritize games over other applications. At the same time, this only works for the one PC that is doing both downloading and gaming. If there are other computers on the network at all, it would be much more cost effective to purchase a router that can handle QoS and bandwidth control on a per application (or per port) basis. Using a router to handle this means that I can download huge massive files on one PC and my wife can play Team Fortress 2 on another without experiencing problems.

I could even play a game on the computer that I'm downloading with in that case, but it remains our recommendation to simply not download in the background while playing a game. More than just networking is affected by downloading in the background, as the harddrive is constantly being hit and this can be a significant source of loading pauses and hitching in and of itself.

If you don't want to spend any money, most torrent and other downloading applications come with built in (or add on) bandwidth controls that can be employed to achieve the same end as hardware QoS. Hardware QoS and bandwidth control are nice features to have, but they are not worth $120.

The voice chat acceleration could be beneficial when gaming while chatting, but currently most applications are not supported. Teamspeak, Ventrillo, and Skype all need out of the box support at the very least. At best we would want all games with built in voice chat to support this as well, but that isn't likely unless and until the hardware becomes more popular. In addition to application support, voice chat doesn't take up a significant amount of CPU time and the most significant impact on latency is still going to be the network as a whole.

TCP/IP offload is a better way to do things, but the benefit to the gamer just isn't there. Network load just isn't high enough to really take advantage of the hardware in modern games. But it isn't like the potential benefit of an NPU can never be realized: it starts to matter in the server space where technology like this was originally targeted. Offloading the CPU of a heavily loaded database server can definitely leave more CPU time for processing tasks and can increase network responsiveness. This just isn't what the Killer Xeno Pro is targeted towards.

So, when you've already got an on-board network card, is the Killer Xeno Pro worth $120-$130 USD? When that money can be put into either CPU or graphics, the answer just has to be no. At the same price as a Radeon HD 4850, there is just no reason not to look toward upgrading older graphics solutions. If you've already got something on the level of the 4850, then that money should be saved for your next graphics hardware upgrade where it will still have a higher impact on performance and experience.

For professional gamers and those obsessed with twitch shooters, for the gamers running 1280x800 on a 30" panel with most of the settings turned down on the highest end hardware money can buy, for those who are always after whatever option might give them the slightest edge: the Killer Xeno Pro might be for you. But even then, this hardware is the icing on the cake rather than a core ingredient.

What the geek inside me really wants to see is more general access to the hardware. This is, after all, a PC on a PCIe card. If Bigfoot gave us deeper access to the hardware, we might find more (even if equally niche) uses for an extra PowerPC processor in our computers. Additionally, to satisfy our intellectual curiosity, we would like to get our hands on a couple more of these cards in order to do some LAN testing using combinations of standard and Killer network cards to see how overall network performance is changed (if at all) especially with respect to voice chat performance.

Beyond this, there is a caveat. Perhaps, as broadband becomes more pervasive, game developers might want to push networking. At some point in time, games may need the PCs they run on to handle a much larger volume of network traffic in order to function well. Right now, game developers are targeting current bandwidths using current commodity network hardware. Games can't be designed to require higher performance networking gear because consumers either don't have access to high speed internet or they don't have a network card that does TCP/IP offload (among other things).

At some point down the line, something like the Killer Xeno Pro might become a significant requirement. But right now, for the vast majority of gamers out there, our advice is to save your money.