4 ms·
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
by pmjordan 15y ago
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.
- ajross 15y agoIf 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.