I'd stick to a single GPU, and you need to go nVidia for F@H as it seems to do a lot better than ATI....and I'm even an ATI fan. I think you should get a GTX680. The GTX770 isn't regarded highly in terms of Folding.

However, apparently the 7970 GHz Edition slightly out-edges the GTX680 in F@H.....I just looked up a review.

 

One note: The GK110 would be worth saving towards, the GTX780 is like $600.....so it might be big-time worth the extra $100.

 

Actually anymore the difference between nvidia and AMD isn't as great. The HD 7970 actually folds core 17 WUs faster than a 680.

Of the two options proposed 2x 760, or 2x 7950s, the 7950s would net you closer to 200k PPD for both cards if you OC them, where the 760s would be slightly lower.

A HD 7950 is a pretty capable folder these days, up to ~80k+ PPD

I don't know the exact numbers on 760s but looking at the number of cuda shaders, I would guess slightly below a 670, which gets ~75k+ PPD. If the 760 is close to that the difference may not be that great.

A single 780 gets up to ~140-150k PPD IIRC.

HD 7970s usually get anywhere from ~95-125k PPD.

On the core 17 WUs the CPU utilization is also lower on the AMD side right now, that could change possibly, I'm not sure. I would also guess the power consumption to be lower on the AMD side as well.

Something NV has over AMD right now in terms of folding GPU support in Linux. Which is the main reason I went GTX 690.

 

If you were here, you'd grab 2 x 7970 OC for the ~ price as a single 780. AFAIK the AMD combo would destroy the Nvidia card running alone.

 

Your best bet at this time is 7970s, look for used or on sale. On average a 7970 is good for 100k PPD without issue, assuming beta units. For reference, a 680 pulls ~85k ppd on the same units (at least mine pulls that), these are all stock numbers, OC will vary per card/person.

I would be leery about spending $600 on a single card for folding, when I dont think titans were doing much more than 150k PPD last I saw (same goes for 780s)

 

I would pick a 7970 for folding, their price is very attractive, the 7970 produce a nice PPD with the core 17 WU's, and also, the 7970 doesn't use a lot of CPU resources IIRC. I'm folding with a GTX 780 and a GTX 570, and I have to fold with SMP 6 on my i7 3770k, leaving 2 cores free for the GPU's. My average las 24hr PPD on this hardware is 188k PPD. Using this combination, Iget 100% of usage on the CPU and GPU's, and according to my watt usage at the wall, 500W of power consumption. You should be ok with a 7970, take a look at reviews, regarding temps, and also, check the warranties, because you will use the gpu 24/7 at full load, so having a nice warranty is always usefull.

 

Quote:

Originally Posted by WFeather

..... , when I dont think titans were doing much more than 150k PPD last I saw (same goes for 780s)

..... it all depends on the projects ......

2x GTX Titan

2x GTX 780

for a short time,

Andy

 

Not fair putting up those over-inflated 8902 numbers...we know they were just a flash-in-the-pan tease!

Quote:

Originally Posted by AndyE

..... it all depends on the projects ......

Spoiler: Warning: Spoiler!

2x GTX Titan

2x GTX 780

for a short time,

Andy

 

Quote:

Originally Posted by scubadiver59

Not fair putting up those over-inflated 8902 numbers...we know they were just a flash-in-the-pan tease!

ok, you are right

Is P8900 ok then?

,
Andy

 

Thanks for the responses guys!

 

The PSU question:

A solid 750W+ should handle a dual GPU setup easily. Before buying more than that decide if you want to have more GPUs running or just upgrade the GPU's to increase PPD down the road. Also make sure your MB has at least 3 slots free for GPUs if you plan on adding more than two.

Really anything over 1k+ is overkill for most systems (a handful of HDD's, a single CPU, and under 3 GPU's).

I have a 1300W but that's because I run 10HDD's, and overclocked 3930k, 4 GPUS, and various other hardware.

EDIT***
More on the 2 GPU's v 4 GPU question.
4 660ti's will net you approx 250-280 ppd with a cost of 800 upfront. (70/card w/ overclock)
3 680's will net you 240-250 ppd with 900$ upfront. (90/card w/ overclock)

 

delete

 

PCIe 2.0 shouldn't be an issue