Folding@Home on dual processor Gentoo/Linux machine

drasnor

It's vacation and I'm moving my entire farm over to Linux. I can install a single instance of Folding by typing

emerge foldingathome

but that only gets me halfway there on my dual processor machines.

Any ideas?

-drasnor

drasnor

Nevermind, I solved my own problem. Basically, just create another Folding directory and modify the initscript.

-drasnor

mmonnin

Glad you got it fixed cause I would have been no help.;)

drasnor

For one reason or another I notice an enormous speedup using Linux over Windows. On the same WU my 1.3GHz Celeron running Gentoo gets the same frame times as each instance on my dual Opterons running Windows XP. I think it has to do with the fact that folding is one of only 5 or 6 processes running on the Linux box whereas it shares processor time with like 40 or so Windows processes on the Opterons.

Not running a GUI probably helps too.

-drasnor

mmonnin

Oh wow!

What type of WUs are those? Gromacs or tinkers?

Do you have any stats from the Windows install that you can compare to the Linux install? Something to compare direct frame times between the OSs.

drasnor

Gromacs.

Unfortunately I didn't keep the logs from when those machines were running Win2k. I just remember it being a somewhat slower than it is now. In any case, this comparison isn't particularly helpful since the platforms are completely different, but here goes.

from Morkeleb (WinXP Pro, 2x Athlon MP 2100+ (Palomino), FAH instance #2 of 2)
[01:11:51] Protein: p724_Abeta21-43-amberGS
[01:11:51]
[01:11:51] Writing local files
[01:11:52] Extra SSE boost OK.
[01:11:53] Writing local files
[01:11:53] Completed 0 out of 125000 steps (0)
[01:23:57] Writing local files
[01:23:57] Completed 1250 out of 125000 steps (1)
[01:36:02] Writing local files
[01:36:02] Completed 2500 out of 125000 steps (2)
[01:48:06] Writing local files
[01:48:06] Completed 3750 out of 125000 steps (3)
Chipset: AMD 760MPX
RAM: 1GB registered ECC PC2100 cl2

from Tiamat (Gentoo Linux, 2x Pentium III Cu 1.1GHz, FAH instance #1 of 2)
[12:16:47] Protein: p724_Abeta21-43-amberGS
[12:16:47]
[12:16:47] Writing local files
[12:16:47] Completed 67115 out of 125000 steps (54%)
[12:16:48] Extra SSE boost OK.
[12:23:36] Writing local files
[12:23:36] Completed 68750 out of 125000 steps (55%)
[12:45:36] Writing local files
[12:45:36] Completed 70000 out of 125000 steps (56%)
[13:07:37] Writing local files
[13:07:37] Completed 71250 out of 125000 steps (57%)
Chipset: Intel i440BX
RAM: 512MB PC100 cl3

It's also worth mentioning that I never could get the SSE boost working with my Opteron system so it's doing straight FPU math. With forceasm turned on, Folding would frequently crash with LINCS errors. The people at Folding Community were less than helpful (to put it mildly) except for one guy who actually read my post instead of just telling me to stop overclocking my $1000 processors (which weren't/aren't overclocked at all).

-drasnor

muddocktor

Yeah, the folding community is full of a bunch of asshats whose stock answer is to stop overclocking instead of actually reading your post.

mmonnin

Well they are about the same with the P3s being at a lot lower clock speed. Sounds pretty nice. Having SSE is pretty much a necessity for working on Gromacs, otherwise production is Severely reduced.

drasnor

As of the latest ebuilds Gentoo takes care of everything for you so you don't need to manually edit the scripts or install multiple instances. Another in a long list of great reasons to use Gentoo.

If you're currently using the old FAH v4 ebuilds you will need to manually unmerge (emerge --unmerge foldingathome) and delete your /etc/init.d/foldingathome script prior to emerging the new ebuild.

-drasnor