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
kyuu - Friday, January 4, 2013 - link
You're the one stepping into the past with the CISC vs. RISC. x86 is not going to go away anytime soon. Keep dreaming, though.iwod - Saturday, January 5, 2013 - link
Nothing about Architectures in this comment, but by the time ARM Cortex A57 is out, so is Intel ValleyView, which doubles the performance. A57 is expected to give in best case scenario 30 - 50% increase in performance. And All of a sudden this look so similar to 2x Atom performance.It will only take one, just ONE mistake that ARM make for Intel to possibly wipe them off the map.
Although looking into the next 3 - 5 years ahead. It will be a bloody battle instead.
Cold Fussion - Friday, January 4, 2013 - link
Why didn't have any charts which were performance per watt or energy consumption vs performance in the GPU area? If the Mali chip is using twice the energy but giving 3x the performance then that is a very significant point thats being misrepresented.mrdude - Friday, January 4, 2013 - link
I was thinking the same thing.If I can game at native resolution on a Nexus 10 at better frame rates than on the Atom or Snapdragon SoC and the battery capacity is larger and the price of the device is equal, then do I really care about the battery life?
Although it's nice seeing Intel is getting x86 down to a competitive level with ARM, the most astonishing thing that I took away from that review was just how amazing that MaliT604 GPU is. All that performance and only that power draw? Yesplz :P
parkpy - Friday, January 4, 2013 - link
i've learned so much from AT's review of the iPhone5, Galaxy S III, and Nexus 4, and this article about mobile phones that it makes me wish AT could produce MORE reviews of mobile devices.All of this information is crack! I can't get enough of it. Keep up the good work! And Intel, I can't wait for you to get your baseband processor situation sorted out!
I was already tempted to get a Razr I, but it looks like before the end of the year consumers will have some very awesome technology in their phones that won't require as much time on the battery charger!
This Guy - Friday, January 4, 2013 - link
What if Rosepoint is software defined instead of fixed function?ddriver - Friday, January 4, 2013 - link
I am confused here - this review shows the atom to be somewhat faster than A15, while the review at phoronix shows the A15 destroying the atom, despite the fact intel's compiler is incredibly good at optimizations and incomparably more mature.So I am in a dilemma on who to trust - a website that is known to be generously sponsored by intel or a website that is heavily focused on open source.
What do you think?
kyuu - Friday, January 4, 2013 - link
Uh, did we read the same article? Where does it show the Atom being "somewhat faster than A15"? The article showed that the A15 is faster than Atom, but at a large power premium.ddriver - Friday, January 4, 2013 - link
On the charts I see the blue line ending its task first and taking less time, blue is atom, right?jwcalla - Friday, January 4, 2013 - link
A couple things:1) The Phoronix benchmarks were for different Atoms than the one used in this article. I don't know how they compare, but they're probably older models.
2) The Phoronix benchmarks used GCC 4.6 across the board. Yes, in general GCC will have better optimizations for x86, but we don't know anything (unless I missed it) about which compilers were used here. If this was an Intel sample sent to Anand, I'm sure they compiled the software stack with one of their own proprietary Intel compilers. Or perhaps it is the MS compiler, which no doubt has decades of x86 optimizations built in and probably less ARM work than GCC (for the RT comparison).
Don't take the benchmarks too seriously, especially since even the software isn't held constant here like it was in the Phoronix benchmarks. It's all ballpark information. Atom is competitive with ARMv7 architectures -- that's the takeaway.