4 ms·
Unless you need the address space, there is little gain with a 64 bit OS. The wider pointers use more RAM and eat up more of the available memory bandwidth and
by gmueckl 7y ago
Unless you need the address space, there is little gain with a 64 bit OS. The wider pointers use more RAM and eat up more of the available memory bandwidth and caches. So not swotching to 64 bits is likely the best use if the hardware.
- saagarjha 7y agoIt’s a toss up, I think: actual results depend on the task at hand. 64-bit has the benefit of more, wider registers, which can speed up certain tasks.
- gmueckl 7y agoI stand corrected. I missed the fact that ARM also introduced new registers in AArch64. I thought that such a change only happened in amd64.
- Narishma 7y agoThe new registers in AArch64 aren't as useful as on AMD64 because ARM wasn't as register-starved as x86 to begin with.
- asveikau 7y agoThe other thing about amd64 is that amd64 code can safely ditch old features like x87 floating point, which is much slower than more recent features. Also, function calls will more frequently pass by register. And I can think of one OS specific feature that is better on amd64: when MS ported to amd64 they took it as an opportunity to speed up the ABI for Structured Exception Handling (SEH). The x86 one incurred a time cost even for code that did not throw. Of course none of this applies to arm/aarch64.