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
Cortex A15: GPU Power Consumption - 3D Gaming Workload
ARM's Mali-T604 GPU is pretty quick, but similar to ARM's Cortex A15s it can definitely use a considerable amount of power to deliver that performance. Peak GPU power consumption tops out at just under 4W compared to ~1W for Qualcomm's Adreno 225. Even the Cortex A15s pull a decent amount of power in this test compared to the alternatives. It seems like that 4W max we keep seeing is likely the typical TDP for the Exynos 5250, anywhere from 1x - 4x what we get with Atom Z2760 and APQ8060A.
The Mali-T604's performance advantage here comes at a price: total energy consumed is far higher than any of the competing solutions.
GPU Power Consumption - Max, Avg, Min Power
Average Power Draw
Minimum Power Draw
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powerarmour - Friday, January 4, 2013 - link
So yes, finally confirming what anyone with half a brain knows, competitive ARM SoC's use less power.apinkel - Friday, January 4, 2013 - link
I'm assuming you are kidding.Atom is roughly equivalent to (dual core) Krait in power draw but has better performance.
The A15 is faster than either krait or the atom but it's power draw is too much to make it usable in a smartphone (which is I'm assuming why qualcomm had to redesign the A15 architecture for krait to make it fit into the smartphone power envelope).
The battle I still want to see is quad core krait and atom.
ImSpartacus - Friday, January 4, 2013 - link
Let me make sure I have this straight. Did Qualcomm redesign A15 to create Krait?djgandy - Friday, January 4, 2013 - link
No. Qualcomm create their own designs from scratch. They have an Instruction Set licence for ARM but they are arm "clones"apinkel - Friday, January 4, 2013 - link
Sorry, yeah, I could have worded that better.But in any case the comment now has me wondering if I'm off base in my understanding of how Qualcomm does what it does...
I've been under the impression that Qualcomm took the ARM design and tweaked it for their needs (instead of just licensing the instruction set and the full chip design top to bottom). Yeah/Nay?
fabarati - Friday, January 4, 2013 - link
Nay.They do what AMD does, they license the instruction set and create their own cpus that are compatible with the ARM ISA's (in Krait's case, the ARMv7). That's also what Apple did with their Swift cores.
Nvidia tweaked the Cortex A9 in the Tegra 2, but it was still a Cortex A9. Ditto for Samsung, Hummingbird and the Cortex A8.
designerfx - Friday, January 4, 2013 - link
do I need to remind you that the Tegra 3 has disabled cores on the RT? Using an actual android device with Tegra 3 would show better results.madmilk - Friday, January 4, 2013 - link
The disabled 5th core doesn't matter in loaded situations. During idle, screen power dominates, so it still doesn't really matter. About all you'll get is more standby time, and Atom seems to be doing fine there.designerfx - Friday, January 4, 2013 - link
The core allows a lot of different significant things - so in other words, it's extremely significant, including in high load situations as well.That has nothing to do with the Atom. You get more than standby time.
designerfx - Friday, January 4, 2013 - link
also, during idle the screen is off, usually after whatever amount of time the settings are set for. Which is easily indicated in the idle measurements. What the heck are you even talking about?