The ARM vs x86 Wars Have Begun: In-Depth Power Analysis of Atom, Krait & Cortex A15
by Anand Lal Shimpi on January 4, 2013 7:32 AM EST- Posted in
- Tablets
- Intel
- Samsung
- Arm
- Cortex A15
- Smartphones
- Mobile
- SoCs
What's Next? ARM's Cortex A15
Comparing to Qualcomm's APQ8060A gives us a much better idea of how Atom fares in the modern world. Like Intel, Qualcomm appears to prioritize single threaded performance and builds its SoCs on a leading edge LP process. If this were the middle of 2012, the Qualcomm comparison is where we'd stop however this is a new year and there's a new kid in town: ARM's Cortex A15.
We've already looked at Cortex A15 performance and found it to be astounding. While Intel's 5-year old Atom core can still outperform most of the other ARM based designs on the market, the Cortex A15 easily outperforms it. But at what power cost?
To find out, we looked at a Google Nexus 10 featuring a Samsung Exynos 5250 SoC. The 5250 (aka Exynos 5 Dual) features two ARM Cortex A15s running at up to 1.7GHz, coupled with an ARM Mali-T604 GPU. The testing methodology remains identical.
Idle Power
As the Exynos 5250 isn't running Windows RT, we don't need to go through the same song and dance to wait for live tiles to stop animating. The Android home screen is static to begin with, all swings in power consumption have more to do with WiFi at this point:
At idle, the Nexus 10 platform uses more power than any of the other tablets. This shouldn't be too surprising as the display requires much more power, I don't think we can draw any conclusions about the SoC just yet. But just to be sure, let's look at power delivery to the 5250's CPU and GPU blocks themselves:
Ah the wonderful world of power gating. Despite having much more power hungry CPU cores, when they're doing nothing the ARM Cortex A15 looks no different than Atom or even Krait.
Mali-T604 looks excellent here. With virtually nothing happening on the display the GPU doesn't have a lot of work to do to begin with, I believe we're also seeing some of the benefits of Samsung's 32nm LP (HK+MG) process.
Remove WiFi from the equation and things remain fairly similar, total platform power is high thanks to a more power hungry display but at the SoC level idle power consumption is competitive. The GPU power consumption continues to be amazing, although it's possible that Samsung simply doesn't dangle as much off of the GPU power rail as the competitors.
Facebook
Twitter
RSS
140 Comments
View All Comments
extide - Friday, January 4, 2013 - link
When will you post an article about Bay Trail / Valley View?? Usually you guys are pretty fast to post stuff about topics like this yet I have seen some info on other sites already...jpcy - Friday, January 4, 2013 - link
...which I bet CISC users thought had ended about 18 years ago...It's good to see a resurgence of this highly useful, extremely low-power and very hardy British CPU platform.
I remember back in the day when ARMs were used in the Acorn computers (possibly too long ago for most to remember, now - I still have an A7000 and a RISC PC with both a StrongARM and a DX2-66 lol) was at war with Intel's Pentium CPU range and AMD's K6's, boasting an almost 1:1 ration of MIPS:MHz - Horsepower for your money (something Intel and AMD were severely lacking in, if I remember correctly.)
And now, well, who'dve thought it... These ARM CPUs are now in nearly everything we use... Phones, smartphones, tablets, notebooks...
Suppose I was right in the argument with my mate in school afterall... RISC, superior technology (IMHO) may well take over, yet!
nofumble62 - Friday, January 4, 2013 - link
No performance advantage, no battery life advantage. Why anyone would bother with incompatible software?sseemaku - Friday, January 4, 2013 - link
Looks like people have changed religion from AMD to ARM. Thats what I see from some comments.mugiebahar - Saturday, January 5, 2013 - link
Yeah n no. They wanted a no paid opinions to screw with the outcome. But Intel hype won over real life .Intel better and will get better - yes
Any chance they will compete (performance and PRICE) and legacy. Support to phone apps - Never in the near future which is the only time for them.
tuxRoller - Saturday, January 5, 2013 - link
Also, any chance for an actual performance comparison between the platforms?Apple's performance and power use look awesome. Better than I had imagined.
I'd love to see how they compare on the same tests, however.
Kogies - Saturday, January 5, 2013 - link
It appears the war has begun, well two wars in fact. The one you have articulately described, and the oft ensuing war-of-words...Thanks Anand, I appreciate the analysis you have given. It is excellent to get to see the level of granularity you have been able to achieve with your balance of art and science, and knowing where to hook into! I am very interested to see how the L2 cache power draw effects the comparison, just a little jitter in my mind. If nothing else, it looks as if the delicate balance of process tech., and desired performance/power may have a greater bearing on this "war" than mere ISA.
With Krait 300, Haswell, and more A15's this is going to be a tremendous year. Keep up the good work.
Torrijos - Saturday, January 5, 2013 - link
Any chance we could see the same tests run on the latest Apple iPad?That way we could have a chance to see what Apple tried to improve compared to the A15 generation.
urielshun - Saturday, January 5, 2013 - link
The whole discussion about ARM and x86 is not important when you go for the ecomonics of each platform. ARM is dirty cheap and works well. It's 1/10th of the price of any current Atom with decent perfomace (talking about RK3066).Don't underestimate the Chinese they are having a field day with ARM's pricing model and and have shown amazing chips.
In 8 years from now all SoC's would have reached the usuable performace and the only thing that will matter will be power and cost of integration.
iwod - Saturday, January 5, 2013 - link
Where are you getting 1/10 of a price from? Unless they are produced on good old 40nm LP Node with Nothing else, or crap included, otherwise there just aren't any Chinese SoC selling for $4