32bit vs 64bit crunching

[Bradtech519]

Is there a difference in performance when crunching from an XP SP3 box and a Windows 7 or Linux 64bit machine?

 

[Ken g6]

On PrimeGrid, definitely. But only on the sieves, so far. I'm not sure about other projects; Collatz might be faster on 64-bit, but I'm not sure.

 

[Bradtech519]

On PrimeGrid, definitely. But only on the sieves, so far. I'm not sure about other projects; Collatz might be faster on 64-bit, but I'm not sure.

Ahh I got a rig on XP SP3 crunching milkyway.. Xeon 2.0 Ghz quad

 

[Assimilator1]

Yea I'd like to know about on F@H on 64bit, I might install Win7 64 soon.

DPAD is slower with 64bit as it hasn't been updated for it!

 

[ZipSpeed]

From my own experience, there's basically no difference for 32 and 64 bit for F@H. The one machine that I moved from XP to 7 produced the same PPD in both OSes.

 

[IGemini]

There's no difference with F@H since it's still an x86-based client.

With BOINC it makes a significant difference, at least as far as the benchmark is concerned. Just going between Windows 32 and 64-bit I saw a 33% increase in Dhrystone performance (RAM-limited, I think), not sure how much each project is dependent on integer calculations, though. Linux managed to muscle even more out of my file server on an old s939 4000+.