Looking to get started with GPU processing

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RE: Hi Zalster, Thanks for


Hi Zalster,

Thanks for the info on Matman's PC. Not sure why a Titan Black would be listed as two GTX750TI when the Titan Black only has one GPU on the card. I could understand maybe a Titan Z being reported as two graphics cards with its two gpus.

Boinc is not setup to distinguish between the gpu's when there is more than one in a system when displaying them that way, so if you see (2)GTX750 gpu's listed it could mean a single GTX750 and something else, or really be two GTX750's. The only way to know is to ask the person, checking their times can help, but with the way some people run their gpu's even that isn't foolproof. One could be running much hotter than the other and therefore an identical card could be running slower due to that heat.

Have you ever used a Refurbished card from EVGA? Reading the reviews I see mixed reviews on the refurbished cards.

I buy refurbished cards from Amazon but only the "Very Good" or better ones. I look for things like "Comment: Item is in original packaging, but packaging has damage. Small (less than 1/4" x 1/4") cosmetic imperfection on front of item."

That kinda tells me it should get to me okay and that it should run just fine. It could also mean it had been run hard but still meets the original specs, I just don't know. But I have had good luck buying this way and saved alot of money on gpu's in the process. I also NEVER buy a gpu with a just single fan on it anymore, if it has problems a single fan can easily mean a burnt up card.

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RE: EDIT: The GTX 960 and

EDIT: The GTX 960 and the some flavors of the R9 are in the $200 price range. Any feedback on those?

The 960 is a great card, but NOT for Einstein. The 128 bit memory bus is too limiting. For energy efficiency, you want the GTX 750 Ti; as many as you can get. I have six GTX 750 Tis (all the same ASUS model, with minimal GPU core factory overclocking) and three GTX 960s (one Gigabyte and two MSI), and have spent some time comparing them on the various projects. With the GTX 750 Ti, the BRP6 work units take about 1 hour 56 minutes, if properly fed by a CPU core. With the MSI GTX 960 (also minimal GPU core factory overclocking), they take about 1 hour 31 minutes, if you apply the P2 memory clock fix as suggested by Extra Terrestrial Apes https://einsteinathome.org/node/197852 (more like 1 hour 43 minutes without the fix). That means that you are paying more for the card, and using more power, without that much gain.

I also have a GTX 970 and a GTX 980, but I use them only for Folding; they would be good on Einstein also, but not as cost-effective or energy efficient as the 750 Ti. However, there is always the question of the number of PCIe slots available, so either of them would do nicely if that is a big factor; they have the 256 bit memory busses. I think I would get the 970 in that case, since the 980 would be in the same boat as the 960 with the limited memory bus width compared to the number of CUDA cores (and cost a lot more), though I have not tried it myself.

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Hi Robert, Never bought a

Hi Robert,

Never bought a refurbished so have no input on that.

Yes stick with single fans as the dual require really good airflow thru the case.

As you can see, lots of options, but I would stick with that 750ti based on your reply.

If you decide later you want bigger, badder, etc, more power, more electricity, more noise, more heat...then we can talk about other GPUs

As far as telling what someone has in their cases, if their machines are public, you can decipher what is in there by view their result pages ;) ( now a bunch of people are running to hide their computers, lol)


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RE: Boinc is not setup to

Boinc is not setup to distinguish between the gpu's when there is more than one in a system when displaying them that way, so if you see (2)GTX750 gpu's listed it could mean a single GTX750 and something else, or really be two GTX750's. The only way to know is to ask the person, checking their times can help, ...

At the cost of a little time clicking through some task pages for completed tasks on the host you might want to figure this out on, you can get a pretty unambiguous answer.

Right now Stan Pope has a host which appears as having two 970 GPUs. If you click through to the task list, select Parkes PMPS XT only, then valid tasks only, and just start right clicking and viewing task numbers from the leftmost column, you'll see that right after startup there is a line in STDERR which reads something like this:
[INFO ] Using CUDA device #0 "GeForce GTX 970" (1664 CUDA cores / 254.41 GFLOPS)
Unlike the generic notation in the host listing, which just tells you that one of the GPUs on the host is of a particular type, this notation tells you that the GPU which started running this task at the start was a GTX970, and further that it carried the device #0 designation.

One down, one to go, and you can stop clicking as soon as you find one that carries the device #1 designation, as you already know this host has two GPUs.

In this specific case, it appears there may be a bimodal distribution of elapsed times, so having found device 0 on choosing a fast job, I tried a slow job, and was rewarded with:
[INFO ] Using CUDA device #1 "GeForce GTX 970" (1664 CUDA cores / 254.41 GFLOPS)
Not a perfectly closed form nor perfectly reliable method, but a lot quicker and more likely to work than sending a PM to the owner.

Gary Roberts
Gary Roberts
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RE: ... Not sure why a

... Not sure why a Titan Black would be listed as two GTX750TI when the Titan Black only has one GPU on the card.

I don't think it represents two 750Tis. I think it's being misrepresented by BOINC as a single 750Ti.

I also see tapir's computer ID: 4610346 at 39 on the Top computers list with what appears to be three GTX750 TI cards unless that is also being reported incorrectly.

Following archae86's advice, that host actually has 2x570s (devices #1 & #2) and a single 750Ti (#0). So, most of the production is coming from older and more power hungry hardware. The 570s seem to be doing tasks in around 7-8K secs (mostly) and the 750Ti in around 11-12k secs.

Apart from that, there is also some evidence perhaps of thermal throttling. On the first page of 20 results, there were two (done by device #1) which took >20K secs. I would imagine it might be quite hard to keep that lot cool. Maybe device #1 is the middle slot of the three and a bit starved for cool air.

For the EVGA GTX 750TI, I was looking at either the base model or the superclocked with a single fan as they do not require an additional power plug and have listed power consumption of 60 watts. The FTW model with dual fans requires a power plug and has a power consumption of 85 watts.

Firstly, the stated power requirements may not be the actual consumption under a particular set of circumstances. I doubt there would be a 25W difference between the two when crunching BRP6 tasks.

Secondly, I would think a more important consideration would be the load on the motherboard power system if you had 3 cards with no external power connectors in place. In such circumstances, external connectors would offer valuable protection to the motherboard and distribute the total power draw across a lot more 12v wires, rather than having everything having to go through just those wires directly connected to the board.

Thirdly, I think the heat-sink design itself (including the use of heat-pipes and the volume of air that is moved across a decent fin area is more important than whether it's single or dual fan. I'm skeptical about claims that dual fans dump more heat internally. My preference is to leave the case open but I fully realise that's not possible for most people. Just make sure you have a good supply of cool air entering the case and good extraction of the hot internal air.

My goal is to get close to the best performance I can get for the dollar and power consumption. My plan would be to use my current i7-920 and place the three GTX750ti in it, moving the GTX650 to my i3-530 without a graphics card. Yes, I know an i7-920 is not exactly a power efficient CPU by today's standards with its 130W TDP, but the system is paid for.

The 750Ti does give good output for the power used. I have mainly 650s and HD7850s, all bought around 2-4 years ago and all running without issue. I have been very happy with the power consumption and task output of HD7850s. An i3 with a single 7850 draws around 165W from the wall when doing 4 GPU tasks and 2 CPU tasks and gets a RAC around 90K. My estimate is that the GPU is drawing around 80-90W. My belief is that a 750Ti would produce around 60-65K RAC and would draw about 60W.

My old 7850s seem to be pretty much on a par in terms of credit/watt. If I were buying more GPUs at the moment (which I'm not), I'd be looking at dual card setups and both the 750Ti and the successor to the 7850 (R9 270 or perhaps R9 270X) would be on the list. I know both AMD cards are further replaced but I've seen both of those at 'throw-out' prices and I was sorely tempted :-). Both were cheap but the 270 was better value since you can just about turn it into a 270X with clock adjustments. The 270 was even cheaper than a 750Ti in my country - very tempting for a card that should give 50% more output at Einstein.


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