Analyzing Intel Core M Performance: How 5Y10 can beat 5Y71 & the OEMs' Dilemma
by Brett Howse & Ian Cutress on April 8, 2015 8:00 AM ESTDOTA 2 Results
DOTA 2 is a multiplayer battle arena game, and for this test we are using the same setup as our Mainstream benchmark, but this time with a full game. At 1600x900, all of the devices should be around 30 fps, and the overall test is about 45 minutes.
The Core i5 once again does a great job throughout this test. The CPU frequencies are dropped to keep the GPU running at full speed. The GPU basically runs at full speed for the duration of this test. The Venue 11 Pro is not so lucky, with it quickly heating up and being forced to throttle both the CPU and the GPU. The ASUS continues its amazing run, and showcases what can happen with a good passive cooling solution. The Yoga 3 Pro is not so lucky, with that pesky 65°C set point rearing its ugly head, which causes a big drop in overall frequency on such a long sustained workload.
The average CPU frequency for this sustained real world gaming workload has even the Core i5 having to give up some CPU headroom to keep the GPU fed with power. The ASUS has a sizable advantage here, and both the 5Y71 devices drop well under their base 1.2 GHz CPU frequency when the GPU is running at maximum.
The GPU is really the story though, since this is a gaming workload. Amazingly the ASUS is only 100 MHz off of its maximum turbo frequency as an average for this 45 minute workload. Both the Dell Venue 11 Pro and the Yoga 3 Pro do not have enough cooling to keep these kinds of sustained GPU loads going.
The Yoga 3 Pro is by far the coolest SoC in almost all of these tests, with its combination of active cooling and a 65°C maximum SoC temperature. The ASUS is far and away the hottest device in this test, but it also does a lot more work than the other Core M devices, and it is not getting any hotter by the end of the test, so the device cooling is doing its job.
It is clear at this point that the ASUS can keep the GPU frequency much higher than the other Core M devices due to the nature of its cooling, and form factor. The DOTA 2 test is really dominated by it. It is much faster in this test than the other Core M devices, and once again due to the single-channel nature of the Core i5, the ASUS even outperforms the Core i5 in this test.
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seapeople - Thursday, April 9, 2015 - link
Won't an over-aggressive turbo actually decrease performance? Processors are generally less power efficient at higher clock speeds, i.e., running at 3GHz is twice as fast as 1.5GHz but generally uses more than 2x the power, and thus more than 2x the heat.In this case, therefore, a processor that races to 3GHz will quickly (and less efficiently) use up its thermal headroom and have to throttle back moreso than a processor that stayed at 2GHz.
It's like a footrace - if the race is 100m long, you're going to finish fastest if you go all out. However, if the race is a mile long, then the guy who starts off sprinting is going to be sputtering along a quarter of the way into the race as the joggers pass him up.
MrSpadge - Friday, April 10, 2015 - link
You are right that with agressive Turbo the chip is running in a less power efficient state initially and will have to throttle a bit earlier than a slower, steadily running chip. but if we're talking about low performance under sustained loads, this doesn't matter: it affects the first few seconds, or 10's of seconds at most, whereas in the following minutes both systems are running at the same power efficient throttled speed, which is basically determined by the system cooling. It's not like the sprinter who's completely exhausted and can't recover.retrospooty - Wednesday, April 8, 2015 - link
I dont think its really all that complicated... If you are looking for raw performance, Core M isnt for you. It is really for low power devices that do basic stuff like browsing, email etc. For that purpose, its one hell of a CPU. That performance level at 4.5 watts is a hefty accomplishment IMOYuLeven - Wednesday, April 8, 2015 - link
I do development on a Core M machine. Instead of carrying 4 pounds of computing power on my back, I let a cloud based development box do the heavy lifting. The plume light Core M notebook is used basically to write the code and give orders to the Dev box. IMHO opinion a far better setup than having scoliosis for the sake of running code locally.mkozakewich - Wednesday, April 8, 2015 - link
It's not for web browsing. That's what Atom is for. A Core-M device is good for all regular core tasks except sustained graphics tasks. I wouldn't get one to game, but it'll be great for anything else.retrospooty - Thursday, April 9, 2015 - link
That is pretty much exactly what am saying. Basic use, core M is fine. Not for high performance requirements.nathanddrews - Wednesday, April 8, 2015 - link
They have taken the exact opposite approach to their SSD design, where they try very hard to offer constant and consistent performance.xthetenth - Wednesday, April 8, 2015 - link
Both make sense from the perspective of increasing perceived speed. With storage, it hanging and being slow is the biggest way it can impact the feel of the device, while processors that trade finishing short tasks much faster for a tiny decrease in how fast they complete long tasks do a lot to achieve a responsive feel.xthetenth - Wednesday, April 8, 2015 - link
Device buyers don't buy devices to get a higher average frequency, they buy things to do what they want without the device holding them up. Look at the benchmarks where the ASUS holds higher average frequencies but the Yoga's higher maximum frequency means it completes tasks faster, and it performs better in the benchmark. That sort of responsiveness is what turbo is for. The time to complete long tasks isn't going to be materially changed but the time to complete short tasks is going to be reduced significantly if the processor can use a quick burst like turbo allows.I'm also pretty sure that most users consider not getting burned by their device a good thing that should continue, incidentally.
StormyParis - Wednesday, April 8, 2015 - link
That's not a real use case though. Real use case is load a page (low CPU), render page (high CPU) read page (low CPU). I don't care how fast my CPU is idling while I'm reading the page, I do care how fast the page renders. It'd be different if I were running simulations.. that's what desktop CPUs are for.