F@H question

[trevinom]

I don't think I've heard anybody talk about this, but I was wondering if memory on a machine has any impact on the speed at which it crunches. Most of my machines have 128 MB of ram. If I increase them to 256, will they crunch faster?

Has anybody tested this out?

Thanks,
Martin

 

[MichaelD]

Heh, I just started F@H yesterday, but I believe I can answer the question, b/c "basics of computing" apply here.

I know that the F@H program uses about 80MB of memory to do it's thing. It stands to reason that if while trying to program work to do, it runs out of System Memory, it would just go to the Swapfile, which would slow down when the work actually begins...but I don't think it would slow down how FAST you get the WU done, b/c that's totally CPU bound.

Somebody chime in here. I think I'm right...but i've been wrong before...in fact, I'm usually wrong....but not this time...I think.

 

[GLeeM]

If it's a dedicated rig that runs just F@H then I don't think more memory would help for CURRENT WUs.

If you use the rig for other stuff and have many programs open that take up much ram, all of the programs would probably not be as responsive.

 

[yelo333]

I've had WUs that go above 128, but they don't come around too often. I'd say no, so long as you run a low-resource OS, without anything else running

 

[osage]

F@H is all about cpu mhz, not too memory intensive.
I used to run 12 rigs with just 128mb as dedicated folders and suffered no ill effects from the small amount of ram.

 

[ProviaFan]

Right now we're having some more complex WUs, in general, so the 80MB figure that MichaelD quoted is what you can expect. In times of leaner WUs, the memory usage can run between 20MB to 40MB (so that noone gets confused, you can't measure F@H memory usage by looking at FAH*.exe and FAHCore_??.exe in the task manager, it is a bit more involved).

In summary, my humble opinion is that for a dedicated cruncher, 128MB is perfect. For a system with general usage, 256MB is much better, and with memory-intensive applications, don't settle for anything less than 512MB.

 

[trevinom]

Thanks for the responses. I don't run anything else on my crunchers and they all have 128MB so I guess I don't have to worry about upgrading.

Martin

 

[Gravity]

Nearly all my crunchers have a gig 0' ram and they don't go any faster. HOpe that helps.

 

[Ghost]

I have an AMD Athlon 3000+ running at ~ 2.0 Ghz. It's completed 5 work units in the time it took my gf's Pent III 600 Mhz system to complete 1/4 of a WU.... of course the sizes of WU's may be different, although from the screen it looked like they both started on the same kind of unit....

Just my 2 cents

 

[Markfw]

Originally posted by: Ghost
I have an AMD Athlon 3000+ running at ~ 2.0 Ghz. It's completed 5 work units in the time it took my gf's Pent III 600 Mhz system to complete 1/4 of a WU.... of course the sizes of WU's may be different, although from the screen it looked like they both started on the same kind of unit....

Just my 2 cents

Between speed differentce, and the architecture difference, the Athlon64 is so far ahead, that you can't even compare them. Also, the size of a WU needs to also be taken into account. If you are using two different names, and both go to team 198, then you couyld compare the weekly average in points, and that would give you a better estimation of the difference in speed.