Folding speed vs. FSB vs. cache vs. RAM

Hi!

I was wondering on how much does FSB speed, CPU cache and RAM speed impact on folding performance.

For example, comparing a Celeron P4 (FSB 400, 128kb cache) with a P4 (FSB 400, 512kb cache) with a P4 (FSB 533/800, 512kb cache), would all fold at the same speed? I'm assuming their all running at the same clock.

How about RAM speed? Does it fold any faster for using faster memory? (i.e. SDRAM vs. DDR 266 vs. DDR 333, etc.)

I'm seriously thinking about building a mini-farm using some spare parts I have lying around, with a bunch of SDR or DDR boards and celerons or P4s, and was wondering if it's worth the extra price of memory (SDRAM I have, DDR I'll have to buy) and CPU (of course the celerons are a lot cheaper).

Thanks.

AFAIK for Tinker WUs, processor speed and FPU power is what matters. For Gromacs, cache, FSB and mem speed have quite a bit affect.

Hmmm...

But do you think that the extra price for a P4 pays off in WU processing? It's just that the price difference between a 400MHz Celery and a 533MHz P4 is relevant, if the performance gap is minimal I prefer the cheapest solution.

I've also thought about using AMDs but can't find a cheap board with onboard video and LAN, at least the CPUs are quite inexpensive and fast.

I would NOT use a celeron for fast crunching. I have a [email protected] Taulatin that will run almost twice as fast as a 1.7 celly. I dont know if its the cache, but if it was me I would spend the extra cash and get a 2.4 533.




cp

You can get a p4pe for under $100, and a 2.4 533 and will run @ 2.7 evan with cheap memory.




cp

This MSI board is pretty cheap considering it has video, sound and lan onboard. I dont know about OCing with this mobo but i'm 100% sure it will work gromacs and tinkers

i thought the advantage with gromacs was using SSE and it had nothing to do with memory.

as far as i know the biggest factors in folding are how strong your FPU is, what core you're folding, clock speed, whether or not you have an SSE capable cpu, how many background services are running and what version (gui or command prompt) of the client you use. in that order too.

historically AMD's have been better folders than P4's but that changed alot with gromacs and now the field is pretty even except AMD's still have the advantage of doing the same work with a lower clock which sort of puts some truth in the PR system AMD has devised.

Yup, the full blown and new-ish P4's are darn fast folders. However, if you're going to build a farm from spare parts, go as inexpensive as you can while realizing that in truth, everything helps your rig fold faster.

Out of the 40+ rigs that are folding for me now, there's every kind of combination of HD, RAM, and AMD cpu imaginable. The rigs with virtually the same components save a faster HD (ATA133 or RAID 0 vs. ATA 100) will fold fasterl

Also, rigs with faster memory will fold faster. Take two rigs with the same everything and use PC2100 and PC3500 and you'll see a drop in frame rate with the faster memory.

I wouldn't build a farm out of Celey's though. You need at least a full blown P4 to get the most advantage out of the new beta core and SSE programming.

In addition, the farm I just built used PC133 Ram with slow 3600 HD's and XP2100's. It's good for about 350-500 points per day depending on the proteins (love those 910's). If they were using kick butt ram and some better drives I might get 400-550 points per day, but it would've cost me DOUBLE the price per layer.

The best bet is to spend the cash on the cpu's and use what ever you can get your hands on for the rest of the gear needed. That's what is going to make the biggest difference.

Wedo

I can say from experiance that all things being equal (same cpu speed) but the machine with a higher fsb, or more cache will turn out wu's faster.





cp

Ok, I think I had the wrong idea about FAH then... with SETI I knew that FSB was crucial to processing speed, whilst cpu clock didn't matter much, but with FAH it seems the opposite.

And as everyone roughly measures their processing power in mhz, I thought the remaining factors (FSB, mem, etc.) were pretty irrelevant, and didn't even bother testing it hehe

In that case I believe the best option is to go to AMD CPUs, my target is to have a mini-farm of 4 machines, probably running 2400+ cpus - they're fast and pretty cheap. Now I just need the right boards for them

I believe that my real problem will be setting up the whole thingy to operate without hard drives, unfortunately I'm not much into linux....

BTW, thanks for the answers and tips!