Reply to post: Re: Where are the benchmarks?

Re: Where are the benchmarks?

Thanks, I just had a deeper look into it and it turns out that in 32 bit mode the Pi 3 is ARMv7, but in 64 bit mode it's ARMv8. Standard Raspbian OS is 32 bit only, so that apparently limits both Pi3 and Pi4 to ARMv7. I suspect that the reason for this is so they can offer a single image to cover all currently supported versions of Pi (which include the 32 bit only Pi2) instead of offering two different versions of Raspbian. Most of their user base probably won't care one way or the other.

I had just relied on looking at /proc/cpuinfo to find out what ARM version my Pi had and hadn't dug further. I still plan to buy a Pi4 for testing, but will probably put a 64 bit version of Debian or Ubuntu on it to get the best performance and improved SIMD support.

I found a blog post where someone ran both 32 and 64 bit benchmarks on a Pi3 (using Debian for the 64 bit) and he got very significant performance improvements by using 64 bit on the same hardware. Even without SIMD, 32 versus 64 bit makes a very significant difference on x86 as well, according to my testing, so that shouldn't be too surprising when it comes to ARM as well.

As Apple would undoubtedly run any hypothetical ARM laptop in 64 bit mode, that needs to go into the ARM versus x86 comparison discussion as well. Start to add all these factors up and an ARM CPU starts to look quite credible from a performance standpoint.

Thanks again, I'll be taking this into account in my future plans.