GTX 650 Ti PPD

[wurmy]

yeah bulldozers share the FPU among 2 cores. 2 cores which have 2 integer units and 1 FP make up a "module" so an 8-core bd is 4-modules.

I am surprised it is unstable at stock settings, even pegged out at 100% it a should be fine at stock, maybe there is something else bad like ram..?

Hmm...I think AMD under-spec'd the stock HSF. I could buy a backplate HSF, and this would work for me since I'm running the box laying down to vent two GPUs, but I'd rather spend the money on better PSUs, GPUs or maybe saving (someday)...for professional mowing equipment!

I had 32G of RAM in the box, but removed one channel of it just in case. The box has been fine since disabling CPU folding.

If I were to hazard a guess, I'd say that ALU contention and ALU efficiency backlog half of the "cores" and they just generate heat while they're "waiting." With integer applications, this wouldn't be a problem, but AMD desktop CPUs seem to be lagging behind Intel CPUs, especially in synthetic benchmarks meant to stress ALU efficiency. Most non-scientific business server loads are integer-based and bound by network and disk and memory-space.

AMD's target audience for Bulldozer and Piledriver does not include us folders since we're a very specialized market as far as consumer-based desktop CPUs go. I think part of their APU strategy is to structure their drivers so that the int procs on the CPU can augment/use SPs on the same die or on an external card.

I haven't been sober enough (or have enough cash) to think about Opteron architecture since it's not something I can spend on in the near future, but I might pony up a bit more up front on my next desktop CPU purchase and go (carefully and sober) with an Intel CPU.

I did more checking in eventvwr and found that the box rebooted itself 3 times in one week even w/1 GPU + CPU folding. 1 was a bad power hit, and the other time was a mild power hit. I had a mid-night reboot after adding a 2nd 650Ti, and figured that the modest PPD from the CPU wasn't worth losing semi-completed 762x WUs.

 

[jebo_4jc]

It's been a while since I had a bulldozer but I ed getting 20-25k ppd this time last year. Maybe the WUs are that much worse now?

 

[wurmy]

It's been a while since I had a bulldozer but I ed getting 20-25k ppd this time last year. Maybe the WUs are that much worse now?

Hmm...my mobo only lets me disable the cores in pairs. I might've read somewhere that each pair of cores is tied to an ALU, and my ASUS bios only allows disabling pairs of cores, so I can't disable the 0,2,4,6 or 1,3,5,7. I have to disable 1&2, 3&4, 5&6, 7&8.

With 2 of the 4 "core pairs" enabled, temps look good at night, so I might enable a 3rd core-pair as long as the temps are stable <-at least until I kill-a-watt it and decide the PPDs aren't worth it.

 

[wurmy]

I would highly suggest the Rosewill Capstone 450's. They are 80+ Gold and actually very nice PSU's and usually about $59 or so. I am using a few in some of my server boxes. They have gotten good marks on reviews, and they are built using a platform from a pretty reputable OEM.

http://www.newegg.com/Product/Product.aspx?Item=N82E16817182066

I would take this over any antec and most corsairs even!


And yeah, this laptop rocks, heh.

Thank you to all for advising me to not risk my folding gear by using cheap PSUs!.

I remembered to use the sponsored link and ordered 1 Capstone from Newegg for $60.

In the next 2-3 weeks, I should be able to do some testing on 3 different identical GPU/CPU/mobos across a few PSUs while idle and under a folding CPU/GPU load.

It's nice to have hobbies that warm the house!