Re:Raspberry Pi OS 32-bit vs. 64-bit Performance
by yjftsjthsd-h on Monday February 07, 2022 @06:11PM
(#30252807)
> I suspect most of the performance improvements came not from being "64-bit", but rather from the new instructions in aarch64 (and even in armv7) over armv6 (which is what the 32-bit Raspbian has to use to be backwards compatible with the first Raspberry). So I don't think it is entirely appropriate to frame the performance improvements due to it going from "32-bit" to "64-bit".
Possible; IIRC, we had the same thing on x86 because the jump to AMD64 meant that you could depend on certain extensions (SSE2?) that didn't exist on all previous processors but which were present on all 64-bit processors. So it became a split where code compiled for 64-bit CPUs knew it could depend on those extensions without even needing a runtime check, which was nice. That said, my understanding is that for data-heavy workloads it really does help to move twice as much data per operation.
Possible; IIRC, we had the same thing on x86 because the jump to AMD64 meant that you could depend on certain extensions (SSE2?) that didn't exist on all previous processors but which were present on all 64-bit processors. So it became a split where code compiled for 64-bit CPUs knew it could depend on those extensions without even needing a runtime check, which was nice. That said, my understanding is that for data-heavy workloads it really does help to move twice as much data per operation.