64 bit version

[Forcinghavok]

Hello, I was wondering if this program is going to become available in a 64 bit version? It is currently 32 bit correct? Couldn't we fold more if it were 64 bit?

Thanks.

[Joe_H]

This FAQ has been answered many times, the important parts of the client software are 64-bit already. The folding cores do the actual folding, they are available in 64-bit. FAHClient, FAHControl do not do actual processing, do not need the extended address space and registers, and consume little resources in terms of CPU time or memory. So going to 64-bits for them would gain you nothing in terms of folding more.

[JimboPalmer]

Just to elaborate on Joe_H's post.

To the best of my knowledge, the GPU vendors no longer provide 32 bit drivers, so if all Folding@Home did was GPU folding, there would be no down side to being 64 bit.

Both the MacOS and Linux versions are all 64 bit. I do not think there has been a 32 bit MacOS in some time. There are still 32 bit versions of Linux, they are unsupported.

32 bit Windows is still supported, I have no idea for how long. (Only one of my ten Windows Boxes is 32 bit, via multiple free upgrading over the years)

If F@H ever supports AVX_512, I suspect they will have to abandon 32 bit support. You need OS support to save all the registers between threads, and AVX_512 has wider registers. (this is why Windows 7 and earlier are not supported for AVX_256 folding, saving AVX_256 registers came in Windows 7 SP 1)

FAHClient deals with internet communication, so does not have to be 64 bit, FAHControl does user interface work, again not needing 64 bit features. Even if it 'ran faster' the internet is always slower, and the user is always slower, so it would just wait for input faster.

The Core_a7 program does CPU folding, it has 32 bit and 64 bit versions. (Core_a8 is in Beta, I have no idea if it has a 32 bit version, I am not in the Beta team)

[bruce]

You've been a victim of the widespread myth is that a simple 64-bit application runs faster than a 32-bit application. FAHClient can be compiled for either a 32-bit or a 64-bit OS but in actual fact the 64-bit version doesn't run any faster. In fact, the 32-bit version uses slightly less RAM, though given the small footprint and the low activity, there really isn't any strong reason for one over the other.

[JimboPalmer]

It is not that you can't gain speed with 64 bit code, but all the 64 bit advantages come out in complex code. Neither user Interface nor communication code are that bound by CPU registers.

When AMD introduced 64 bit code they added additional registers so you can be more register bound than memory bound, but this code does not need many registers.



For the Cores, additional registers may well be an advantage. And they are available in 64 bits.