The "Apple A5" SoC still uses ARM Cortex-A9 cores like nearly every other mobile SoC. Only one that doesn't is Qualcomm's Snapdragon, which uses their custom (but still based on ARMv7 like the Cortex chips) "Scorpion" design, soon to be succeeded by "Krait". They're still ARM though, the difference isn't near as drastic as PPC v. Intel; it's closer to Intel v. AMD.
No, it doesn't. It's still mostly a software issue. As you can see a dual core 1.2 Ghz GS 2 gets 3300 ms, while a dual core 1.2 Ghz Droid RAZR gets 2000 ms. And that's just the stock browser. It can even get 1300 ms in Firefox.
The A5 still uses 2 Cortex A9 cores. Whatever optimizations Apple has done to it will have a minimal impact on performance. The biggest gains will still be obtained on the software side.
> "Whatever optimizations Apple has done to it will have a minimal impact on performance."
I agree in general, though I think Apple is going to continue adding custom DSPs to their package. And that will provide an advantage in those targeted areas that software alone will not be able to bridge.
Yep, hopefully these will be the days where we understand that comparing numbers such as processor speed when literally everything else in the stack, both hardware and software, is different is a completely pointless exercise.
(EDIT: I know that a JavaScript benchmark isn't an example of this, this is more a general comment on people comment on phone specs at the moment).
As others have said, unless you're only changing one element in the hardware/software stack, it's not an apples-to-apples comparison. However, A5 is reported to use out-of-order execution, whereas A4 and earlier iPhone CPUs are purely in-order. Integer ALU pipeline length has reportedly also been reduced. The memory bus clock has also been doubled. All else being equal, a single A5 core should therefore beat the A4 on identical code. With a different JS engine on a different browser running on a different OS, I doubt these architectural effects will be noticeable.
If you want to talk about architecture, please use the name of the CPU core and not Apple's marketing name for the integrated SoC IC. The "A5" is not a CPU. The application CPUs on the chip are ARM Cortex A9's. These are the same cores that are available on the OMAP4, Exynos, Tegra 2, and a few others I can't remember off the top of my head.
It is indeed a SMP core (1-4 CPUs), which does out of order execution and register renaming. And it outperforms the Cortex-A8 (an in-order CPU) on a per-clock basis on many workloads.
But it's not an Apple part. Everyone is shipping these things now.