32 bit VS 64 bit

[JerWA]

I dunno, I don't run any 32 bit OS. 2 GB? 3 GB with a BIOS hack? Pfeh, need more RAM than that.

One of the GPU app guys could tell you. Slicker, or the guy that runs Collatz?

[Steve Bohlen]

This may be a stupid question but, would the OS make any difference for GPU crunching?

I'd like to see this question answered as well. I'm looking at some upgrade options and this fact could direct me in one direction instead of another.

[Maxwell]

I'd like to see this question answered as well. I'm looking at some upgrade options and this fact could direct me in one direction instead of another.

Which GPU type are you thinking? ATI or CUDA?

[joker]

Which GPU type are you thinking? ATI or CUDA?

I want my beer and to drink it too......Both.

[Maxwell]

I want my beer and to drink it too......Both.

You can rock both in the same box easy in Win7x64. I've never run Linux, so I can't speak to it. I've heard Linux is a bit tough with ATI, though someone with more Linux experience will have to speak to it.

[Slicker]

Yes. 64-bit is better. If you aren't chasing MMs on all projects that is. It won't make any difference on projects which don't take advantage of the 64-bit features. For ones that do, you will see a lot more than a 20% increase. For several, it is a 100-150% increase. Which ones?

PrimeGrid - any of the sieve projects but specifically 321 Sieve and PPS. PPS is the best paying project for 64-bit. I have a box getting 118,000 credits per day on PPS and that is CPU ONLY! Nope. That is not a typo.

AQUA - pays about double.

Collatz - pays more than doulbe for 64-bit than the 32-bit since the 32-bit platorms does 64-bit emulation. Emulation is still faster than using twice as many 32-bit integers (and therefore twice as many calculations for the same WU) if x86 intrinsics are available.

Windows vs Linux vs OS X 64-bit?
Windows usually edges out Linux since most projects use the gcc compiler for Linux. That's not necessarily because GCC is bad, but because developers have to use an older version of GCC to maintain backwards compatibility with older linux distros. If the project uses the Intel compiler for its apps (e.g. can afford a couple thousand dollars to purchase the Intel compiler), it will do better than GCC - at least for Itel CPUs. AMD will actually run slower than GCC since Itel doesn't spend much time optimizing for AMD.

OS X is just BSD Unix with a fancy UI (let the falming being!) so it also uses GCC. Once again, for backwards compatibility with OS X 10.4, gcc 3.3 is used (current version is 4.5 in comparison).

[joker]

Thank you Slicker.