680 vs 670

5pot
5pot
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Topic 196330

These Kepler series take some time to figure out for crunching. Despite the 680 have one more SMX, currently it is somewhat difficult to find a difference at this project.

My EVGA 680 (on x79 3820), I found out that when adding multiple tasks per GPU (3), that there is a sweet spot that must be aligned with core clock and mem clock for GPU utilization to be high. For example, if you overclock the core, but not the memory, the GPU usage is pretty sporadic. Usually will jump around between 70-90%. You have to increase that memory in order for the GPU to work as it should. I have my core @1200, and my memory @3100. If the memory gets to the point where it's "outpacing" my core speed, my GPU usage becomes fluttery again. At these settings it hovers around 88-91% usage. With each task taking between 55 min- 1hour. This equals to around 1200 seconds a piece if they were running 1 at a time (1 hour/3)

On my Gigabyte 670 (2500k) (excellent cooling btw), fans @50% gives me temps of 52C. My current clock is @1242 which is an offset of +43. Since I've only had it in since last night I've been trying to get it to work like my 680, but until 30 min. ago I couldn't figure it out. I had figured I wouldn't need as high of a memory overclock, since less cores, I figured I wouldn't need as much memory. The GPU usage @3tasks was ALL OVER THE PLACE (65-90) jumping constantly. So after I turned it up to +175, it suddenly even out to 88-92% usage. It also looks like tasks will be taking the same amount of time as my 680@1200 (55min-1hour).

So for this project, I must say, unless you plan on overclocking your 680 out of control, it's kinda hard to ignore the 670 for $100 less with a non-reference cooler. A 680 non-reference is I think $530, so it's $130 more. Pretty impressed with how the 670 performs. Took some time to figure out that your memory clock (offset), needs to be higher than your core clock speeds in order to get these cards to function properly when overclocking.

They truly are being choked by the 192-bit bus.

Jeroen
Jeroen
Joined: 25 Nov 05
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680 vs 670

Thank you for sharing your results.

I have not done too much memory tweaking but will start looking into that for further optimization. Unfortunately, since I am running Linux, I do not have a way to see GPU usage with the latest drivers and running nvidia-smi. I can see memory usage however which is 527 MB for two tasks. I am currently running 1175 MHz core and 3104 MHz memory which seems to be doing good for BRP4 but I would be curious to see what additional memory frequency adjustments can do for optimizing performance with this project.

With electric costs set higher during the summer, I was thinking the 670s would be a good choice for adding additional GPUs and the $100-$130 price savings is a nice bonus as well. Glad to hear the performance is similar between the two card types for this project.

5pot
5pot
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Linux tends to have a higher

Linux tends to have a higher utilization than W7, which is probably why yours are.finishing a little faster than mine. Our settings are near identical.

Jeroen
Jeroen
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Have you read about the new

Have you read about the new GK110 Tesla card in the works by NVIDIA:

http://www.nvidia.com/content/tesla/pdf/NV_DS_TeslaK_Family_May_2012_LR.pdf

http://www.nvidia.com/content/PDF/kepler/NVIDIA-Kepler-GK110-Architecture-Whitepaper.pdf

According to the whitepaper, the card has 13 - 15 SMX units with 192 cores each for up to 2880 CUDA cores. The GK110 also has significantly improved double precision performance which would be good for those BOINC projects that require DP. I would be interested to see how this card will handle BRP4 (single precision) compared to current GK104.

5pot
5pot
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Oh I'm sure it will be a

Oh I'm sure it will be a beast. Optimization from the project though is crucial. Currently this project uses CUDA 3.1 Kepler series cannot even be taken full advantage of at this point (I would ASSUME). Unless there is so much that has to be done on the CPU that it's irrelevant. I remember seeing a graph on these forums about how this project seems to "hit a wall" in terms of better GPUs getting more work done. Think it stopped around the 560Ti-570. I still love the lower and lower TDP and less heat. NVIDIA did a good job, just takes some time learning these new cards though and how to OC them correctly.

It does look incredible. Hopefully we should see a GeForce version sometime next year (March again maybe).

I guess I better start saving now......

Snow Crash
Snow Crash
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5pot - I really like the

5pot -

I really like the cherry slice of XtremeSystems team pie and you've been getting very, very close lately. I have a 670 on the way early next week and will be running it 24/7 to keep you at bay.

I appreciate you for doing the tweaking and posting your findings :clap:

All in good fun and crunching,
Steve

--------------------------
- Crunch, Crunch, Crunch -
--------------------------

5pot
5pot
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Well that 670 will definitely

Well that 670 will definitely push you ahead. They're great cards, especially power usage wise. Once GPUgrid opens back up for 6xx series with their new CUDA 4.2, I will be switching back over there. I do enjoy crunching here in the mean time though. Prefer medical/tech crunching myself (trying to come up on Stoneageman in the long run, lol, but got a LONG WAY to go before then)

Didn't realize I was that close on your tail. :)

Enjoy your new card. New drivers should be coming out right when you get your card, Tuesday I believe, so keep an eye out on NVIDIA's website.

Cheers

5pot
5pot
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BTW Congratulations on

BTW Congratulations on finding a pulsar Jeroen!!!!

Jeroen
Jeroen
Joined: 25 Nov 05
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Credit: 738,423,020
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RE: BTW Congratulations on

Quote:
BTW Congratulations on finding a pulsar Jeroen!!!!

Thanks! I feel very fortunate to have been able to contribute to the project in such a way.

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