I believe it was Josh Ho who responded to me a month or so ago and said that it's still coming. My hope is that is still the case, but if they decide to not review it I doubt that they'll announce a non-review:)
The purpose is to have the faster cores shut down when not in use, to save power by running off the slower chips. Then when demand is high, kick in the higher power chips.
But since very few things are very multi-threaded, it is still kind of a waste. Since fast dual core chips keep up in most cases.
The two core clusters will have transistors tuned for different power & performance targets. Up to 1 Ghz the slow ones are more power efficient, whereas the higher frequencies can only be reached by the fast ones. Not sure how much power this actually saves, but Qualcomm has made quite a few simulations before creating such a chip.
They're not the same cores. The A53 is just a logical design for a processor. It is not an implementation, thats left up to the designer and the fab. Depending on your goals, you can optimize for area, power or performance.
Synopsis had a good presentation on the work they did with the A7:
As you can see, the actual layout has an enormous influence on the power/performance tradeoff. As the A53 is descended from the A7, similar tradeoffs likely apply. If they're aiming for a 70% difference in clock, they have a lot of room to optimize the layout on the low power core for minimal leakage.
Forget multi threading. A typical, modern os uses many, many (kernel) threads at a given time. From handling hardware to timers to the actual programs. It's cheaper to run them on different cores, then shut down the cores, than time share a single, or few, cores. Of course this requires an excellent scheduler.
Forget multi threading. A typical, modern os uses many, many (kernel) threads at a given time. From handling hardware to timers to the actual programs. It's cheaper to run them on different cores, then shut down the cores, than time share a single, or few, cores. Of course this requires an excellent scheduler.
The Snapdragon 615 kind of steals the wind from nVidia's sails. At least from a CPU point of view. Same CPU setup, but in a device that will be shipping soon. As opposed to just releasing an SoC with no contracts yet.
This phone does have a very "iPhone 6" look to it.
CPU setup is very different between the SD615 and the X1.
The SD615 has 8x Cortex-A53 CPUs, configured using big.LITTLE across quad-core clusters. 4x Cortex-A53 at 1.7 GHz (big cluster) and 4x Cortex-A53 at 1.0 GHz (LITTLE cluster). 8 of the same CPU cores, just clocked differently.
The X1 has 4x Cortex-A57 for the big cluster, and 4x Cortex-A53 for the LITTLE cluster. Note the difference in the last number in the CPU core name for each cluster.
The snapdragon 808 is the one to look out for. It has, IMHO, the ideal combination of cores. Unfortunately they skimped on the gpu (adreno 418, iirc, but, in practice, it's around adreno 420 levels, but built on a smaller node). Although it shouldn't be neccessary given a power aware scheduler (which STILL isn't good enough in linux), the option to completely prevent certain cores from ever switching on could lead to a better experience. Especially on 4 + 4 big.LITTLE, where you only allow two big cores, and in particular the cores that are farthest apart from one another, to run on the big core side of things. The a53s should be cool enough to not be an issue.
How are 2 A53 clusters not HTC's fault? There's the Snapdragon 610 which is all but identical except it drops the second A53 cluster. (I bet though it's the same chip but with the second cluster simply disabled.) But marketing is all cores, cores, cores. Plenty of phones announced with snapdragon 615 but none with 610...
An A53 cluster is pretty small, so having a low power one as a "little" configuration is nice. But using 4 A53 as BIG cluster is just plain stupid, 2 A57 would be a far better choice. They'd be significantly faster most of the time and in contrast to a cluster of 4 A57 one could actually use their frequency headroom in a phone.
Well 2x A57 + 4x A53 is probably ideal for this market, but it doesn't really exist yet. That's Qualcomm SD 808, stated to be available in Q2 this year. So right now, HTC uses what's available, and that's SD 615.
As as someone else mentioned, the Asia Pacific region wants more cores, so that's what the Asia Pacific region gets. HTC tried its hand at "educating consumers" with the UltraPixel fiasco. It flopped massively in Asia. I don't blame a company that tries to ride the wave instead of swimming against it, when every other company does the same (bar Apple, which really is its own market).
The only problem with the SD 808 is the compromised GPU. If they made a 2xA57 + 4xA53 with the top end GPU, that would be awesome! Heck, I bet even a 2+2 setup would be fine.
Good point about SD 808 not being available yet. And I agree, 2+2 A53/A57 sounds ideal for a phone to me. Although 4+2 would have an advantage in some applications if all cores could be used at once. Like running a highly threaded load on all low power cores and the high power cores at "medium throttle", whatever still fits the power limit. In such cases efficiency should be better than simply running the big cores at full throttle.
But regarding the GPU: is the GPU really limiting you in what you can do with your phone?
They can, and will, all be used at once. Global Task Switching. The problem is deciding which processes to run on which cores. It's an ongoing issue, one that no one has solved for arbitrary loads, but it's being worked on.
To elaborate on what wilco1 has said, big.LITTLE is about matching load to cores, and, in turn, minimizing power draw. big.LITTLE allows for a larger dynamic range of loads than any individual core, and provides lower latency core transitions than with dvfs (although they obviously use dvfs as well). The hardware is now available, and, in the future, you should see even larger differences between big.LITTLE archs as the big cores become increasingly OoO. The software, however, is not yet where it needs to be in order to best take advantage of big.LITTLE. It's a very hard problem.
That's the key point. Four Cortex-A53 cores are much cheaper, much smaller (in terms of die size) and more power efficient than two A57 cores. And when clocked at speeds of 1.7 GHz or higher, even single-core performance is quite acceptable (about two times that of Snapdragon 400, and not that far from Snapdragon 801).
Just the inclusion of Cortex-A57 cores on a chip increases cost and power/heat management requirements significantly. That can make the difference between a device that costs $200 to make (with Cortex-A57 cores) vs. one that costs below $100 (for example, Snapdragon 615, just Cortex-A53 cores, 32-bit memory interface etc).
I expect even high-end devices with eight Cortex-A53 cores clocked at a high frequency to be competitive, especially because of reduced cost and low power. There are also indications that Cortex-A53 is scaling much better on newer processes than Cortex-A57 (more gains on power efficiency and performance when going from 28nm to 20nm, for example). That should be apparent when 20nm parts with just Cortex-A53 cores appear on the market.
"I still believe having two clusters of Cortex-A53s is silly, but HTC weren't the ones making that decision so it's not something I can really fault the phone itself for."
How is the SoC choice not HTCs responsibility? You can't blame Walmart for it but HTC is the one to blame for it's choices. Things like this compromise the credibility of the site. Anyway, at least they go with 1.7GHz so the perf will decent. The iphone 6 Plus size is disturbing, they really need to get rid of this frame in frame design - or maybe they'll add 1 more frame to make it even more meta.
You are right. Unless Qualcomm forced HTC to make this phone using its chips, I do not see how it is not HTC's decision that is responsible for design of this phone.
I wish the reviewers had a refrain but these days all these reviewers are nothing more than predisposed fanboys with big mouths, throwing out judgmental calls as if they are playing politics and favors. Very arrogant and unprofessional.
I think going with the 615 is a marketing gimmick really. I read a review by Anand pointing out that 8 cores is pretty much an unspoken requirement in the China market. So I guess HTC is going along with it so that they have a chance in China. Who wouldn't at the point since it is one of the biggest market and probably not as saturated at this point.
The nexus 9 and especially the denver review is the only thing I have been waiting for anandtech. iPad Air 2 doesn't even come close. Though I have already bought a shield tablet because 16GB on a $400 tablet without microsd is extremely stupid and so limiting as to be useless.
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PeterCollier - Tuesday, January 6, 2015 - link
So that nexus 9 review ... did Anand make a new years resolution to actually review stuff in a timely manner?Stuka87 - Tuesday, January 6, 2015 - link
You do know Anand has not worked for the site for many months now right? And its owned by a different company?LemmyB - Tuesday, January 6, 2015 - link
They're probably still busy reviewing the Nexus 10. I'm sure it'll be right after :-)tuxRoller - Saturday, January 10, 2015 - link
I believe it was Josh Ho who responded to me a month or so ago and said that it's still coming.My hope is that is still the case, but if they decide to not review it I doubt that they'll announce a non-review:)
Someguyperson - Tuesday, January 6, 2015 - link
Having 8 A53 cores in a smartphone is a complete waste, but that's what the Asia-Pacific region wants, so that's what the Asia-Pacific region gets.Flunk - Tuesday, January 6, 2015 - link
It's not a complete waste, it does use more power than a 4-core A53 chip!saratoga4 - Tuesday, January 6, 2015 - link
Actually it should be more power efficient than a typical 4 core A53 chip, since you have the lower power optimized cluster too.Stuka87 - Tuesday, January 6, 2015 - link
The purpose is to have the faster cores shut down when not in use, to save power by running off the slower chips. Then when demand is high, kick in the higher power chips.But since very few things are very multi-threaded, it is still kind of a waste. Since fast dual core chips keep up in most cases.
kpkp - Tuesday, January 6, 2015 - link
The cores are the same, can't you just scale the V/frequency, it sounds more efficient then migrating processes.MrSpadge - Tuesday, January 6, 2015 - link
The two core clusters will have transistors tuned for different power & performance targets. Up to 1 Ghz the slow ones are more power efficient, whereas the higher frequencies can only be reached by the fast ones. Not sure how much power this actually saves, but Qualcomm has made quite a few simulations before creating such a chip.Stuka87 - Tuesday, January 6, 2015 - link
First, yes you can scale V/Freq, turbo mode in Intel and AMD chips do this, as do nVidia and AMD GPUs. Its very common.Second, if you looked you would see four cores are 1.7GHz, and four are 1GHz.
saratoga4 - Tuesday, January 6, 2015 - link
They're not the same cores. The A53 is just a logical design for a processor. It is not an implementation, thats left up to the designer and the fab. Depending on your goals, you can optimize for area, power or performance.Synopsis had a good presentation on the work they did with the A7:
http://www.synopsys.com/Services/Documents/pwr-cen...
As you can see, the actual layout has an enormous influence on the power/performance tradeoff. As the A53 is descended from the A7, similar tradeoffs likely apply. If they're aiming for a 70% difference in clock, they have a lot of room to optimize the layout on the low power core for minimal leakage.
tuxRoller - Wednesday, January 7, 2015 - link
Forget multi threading. A typical, modern os uses many, many (kernel) threads at a given time. From handling hardware to timers to the actual programs.It's cheaper to run them on different cores, then shut down the cores, than time share a single, or few, cores.
Of course this requires an excellent scheduler.
tuxRoller - Wednesday, January 7, 2015 - link
Forget multi threading. A typical, modern os uses many, many (kernel) threads at a given time. From handling hardware to timers to the actual programs.It's cheaper to run them on different cores, then shut down the cores, than time share a single, or few, cores.
Of course this requires an excellent scheduler.
Stuka87 - Tuesday, January 6, 2015 - link
The Snapdragon 615 kind of steals the wind from nVidia's sails. At least from a CPU point of view. Same CPU setup, but in a device that will be shipping soon. As opposed to just releasing an SoC with no contracts yet.This phone does have a very "iPhone 6" look to it.
phoenix_rizzen - Tuesday, January 6, 2015 - link
CPU setup is very different between the SD615 and the X1.The SD615 has 8x Cortex-A53 CPUs, configured using big.LITTLE across quad-core clusters. 4x Cortex-A53 at 1.7 GHz (big cluster) and 4x Cortex-A53 at 1.0 GHz (LITTLE cluster). 8 of the same CPU cores, just clocked differently.
The X1 has 4x Cortex-A57 for the big cluster, and 4x Cortex-A53 for the LITTLE cluster. Note the difference in the last number in the CPU core name for each cluster.
Stuka87 - Tuesday, January 6, 2015 - link
Ahh, you are right.tuxRoller - Saturday, January 10, 2015 - link
The snapdragon 808 is the one to look out for. It has, IMHO, the ideal combination of cores. Unfortunately they skimped on the gpu (adreno 418, iirc, but, in practice, it's around adreno 420 levels, but built on a smaller node).Although it shouldn't be neccessary given a power aware scheduler (which STILL isn't good enough in linux), the option to completely prevent certain cores from ever switching on could lead to a better experience. Especially on 4 + 4 big.LITTLE, where you only allow two big cores, and in particular the cores that are farthest apart from one another, to run on the big core side of things. The a53s should be cool enough to not be an issue.
Megatomic - Tuesday, January 6, 2015 - link
Not a bad looking device, it would be a pretty nice upgrade from my Moto X 2013.mczak - Tuesday, January 6, 2015 - link
How are 2 A53 clusters not HTC's fault?There's the Snapdragon 610 which is all but identical except it drops the second A53 cluster.
(I bet though it's the same chip but with the second cluster simply disabled.)
But marketing is all cores, cores, cores. Plenty of phones announced with snapdragon 615 but none with 610...
MrSpadge - Tuesday, January 6, 2015 - link
An A53 cluster is pretty small, so having a low power one as a "little" configuration is nice. But using 4 A53 as BIG cluster is just plain stupid, 2 A57 would be a far better choice. They'd be significantly faster most of the time and in contrast to a cluster of 4 A57 one could actually use their frequency headroom in a phone.aryonoco - Tuesday, January 6, 2015 - link
Well 2x A57 + 4x A53 is probably ideal for this market, but it doesn't really exist yet. That's Qualcomm SD 808, stated to be available in Q2 this year. So right now, HTC uses what's available, and that's SD 615.As as someone else mentioned, the Asia Pacific region wants more cores, so that's what the Asia Pacific region gets. HTC tried its hand at "educating consumers" with the UltraPixel fiasco. It flopped massively in Asia. I don't blame a company that tries to ride the wave instead of swimming against it, when every other company does the same (bar Apple, which really is its own market).
extide - Tuesday, January 6, 2015 - link
The only problem with the SD 808 is the compromised GPU. If they made a 2xA57 + 4xA53 with the top end GPU, that would be awesome! Heck, I bet even a 2+2 setup would be fine.MrSpadge - Wednesday, January 7, 2015 - link
Good point about SD 808 not being available yet. And I agree, 2+2 A53/A57 sounds ideal for a phone to me. Although 4+2 would have an advantage in some applications if all cores could be used at once. Like running a highly threaded load on all low power cores and the high power cores at "medium throttle", whatever still fits the power limit. In such cases efficiency should be better than simply running the big cores at full throttle.But regarding the GPU: is the GPU really limiting you in what you can do with your phone?
tuxRoller - Saturday, January 10, 2015 - link
They can, and will, all be used at once.Global Task Switching.
The problem is deciding which processes to run on which cores. It's an ongoing issue, one that no one has solved for arbitrary loads, but it's being worked on.
StormyParis - Tuesday, January 6, 2015 - link
The whole point of big.LITTLE is that you've got the same number of big and little cores, which makes switching easier.Wilco1 - Wednesday, January 7, 2015 - link
No, big.LITTLE does not require the same number of big and little cores. With global task switching you can run all cores simultaneously if required.tuxRoller - Saturday, January 10, 2015 - link
To elaborate on what wilco1 has said, big.LITTLE is about matching load to cores, and, in turn, minimizing power draw. big.LITTLE allows for a larger dynamic range of loads than any individual core, and provides lower latency core transitions than with dvfs (although they obviously use dvfs as well).The hardware is now available, and, in the future, you should see even larger differences between big.LITTLE archs as the big cores become increasingly OoO. The software, however, is not yet where it needs to be in order to best take advantage of big.LITTLE. It's a very hard problem.
saratoga4 - Tuesday, January 6, 2015 - link
4 A53s are much cheaper than 2 A57s. Remember, this is a midrange to budget part.Vegator - Saturday, January 10, 2015 - link
That's the key point. Four Cortex-A53 cores are much cheaper, much smaller (in terms of die size) and more power efficient than two A57 cores. And when clocked at speeds of 1.7 GHz or higher, even single-core performance is quite acceptable (about two times that of Snapdragon 400, and not that far from Snapdragon 801).Just the inclusion of Cortex-A57 cores on a chip increases cost and power/heat management requirements significantly. That can make the difference between a device that costs $200 to make (with Cortex-A57 cores) vs. one that costs below $100 (for example, Snapdragon 615, just Cortex-A53 cores, 32-bit memory interface etc).
I expect even high-end devices with eight Cortex-A53 cores clocked at a high frequency to be competitive, especially because of reduced cost and low power. There are also indications that Cortex-A53 is scaling much better on newer processes than Cortex-A57 (more gains on power efficiency and performance when going from 28nm to 20nm, for example). That should be apparent when 20nm parts with just Cortex-A53 cores appear on the market.
patinio - Tuesday, January 6, 2015 - link
5.5 inch screen, 189 grams and only 2600 mAh battery? I don't get it why they couldn't fit a larger battery in such a big bodyjjj - Tuesday, January 6, 2015 - link
"I still believe having two clusters of Cortex-A53s is silly, but HTC weren't the ones making that decision so it's not something I can really fault the phone itself for."How is the SoC choice not HTCs responsibility? You can't blame Walmart for it but HTC is the one to blame for it's choices. Things like this compromise the credibility of the site.
Anyway, at least they go with 1.7GHz so the perf will decent. The iphone 6 Plus size is disturbing, they really need to get rid of this frame in frame design - or maybe they'll add 1 more frame to make it even more meta.
Klug4Pres - Tuesday, January 6, 2015 - link
"How is the SoC choice not HTCs responsibility?"Agreed. One of the more ridiculous comments I have seen in a review.
x748in1s - Wednesday, January 7, 2015 - link
You are right. Unless Qualcomm forced HTC to make this phone using its chips, I do not see how it is not HTC's decision that is responsible for design of this phone.I wish the reviewers had a refrain but these days all these reviewers are nothing more than predisposed fanboys with big mouths, throwing out judgmental calls as if they are playing politics and favors. Very arrogant and unprofessional.
watzupken - Tuesday, January 6, 2015 - link
I think going with the 615 is a marketing gimmick really. I read a review by Anand pointing out that 8 cores is pretty much an unspoken requirement in the China market. So I guess HTC is going along with it so that they have a chance in China. Who wouldn't at the point since it is one of the biggest market and probably not as saturated at this point.schadenfreude000 - Tuesday, January 6, 2015 - link
Being *that* guy - the OS section of the specs table should read "Android 5.0 Lollipop with HTC Sense".Fergy - Wednesday, January 7, 2015 - link
The nexus 9 and especially the denver review is the only thing I have been waiting for anandtech. iPad Air 2 doesn't even come close. Though I have already bought a shield tablet because 16GB on a $400 tablet without microsd is extremely stupid and so limiting as to be useless.Chozhan - Wednesday, January 7, 2015 - link
Does this phone support EV-DO REV B like HTC 816......can you suggest other smartphones which support evdo rev b.....thnxgigabies - Thursday, January 8, 2015 - link
Android 5.0 is Lollipop but u mentioned as kitkatnodiaque - Friday, January 9, 2015 - link
I think there's a mistake:Operating System Android 5.0 KitKat with HTC Sense
I think you mean Android 5.0 Lolipop