Not exactly a high end card, but here it is:

Zotac GTX 260
base clock 576 core/1242 shader/1000 memory
OC to 701 core/1512 shader/1100 memory
73°C max @ 55% fan

At these settings the card has excellent stability, only had one WU error that I'm not convinced was related to the overclock. TBH I'm not sure the memory OC is even necessary, I don't think this project uses enough memory bandwidtch for it to be relevant. I believe this card can go higher but I haven't tested it yet. This is under Windows 7 using MSI Afterburner.

I'm using Windows XP x64 (and x86 too).
I've overclocked my GTX 480s to 800MHz@1050mV, GTX 580 to 850MHz@1063mV, GTX 590 to 720MHz@925mV and 913mV (memory clocks at factory settings on all cards)
Also, I've changed the GPU coolers to Arctic Cooling Accelero Xtreme Plus, so the GPU temps are way below 70°C (except on my GTX 590, which still has the standard cooler plus a 12cm cooler directly above the card, it goes up to 83°C sometimes)
A 80+ Gold (or even a 80+ Platinum) certified power supply is recommended for overclocking, with an adequate headroom for the extra power needed. It's not recommended to use a PSU above 75% of its nominal wattage in long term. (Considering efficiency and longevity)
Remember: the power consumption is in direct ratio with the frequency, but in square ratio with voltage (so 10% more voltage causes 21% more power consumption since 1.1*1.1=1.21), and these adds up.
At higher temperatures the power consumption of a chip goes even higher.
At higher temperatures a chip tolerates less overclocking.
10°C (or K) rise in the chip's operating temperature halves its lifetime (actually its MTBF).
Higher overclocking may work with lesser GPU utilizing workunits, but the highly GPU utilizing tasks may fail with those settings.
To make overclocking worth the effort, workunits should not fail at all. It's easy to loose the 10-15% gain of overclocking by failing workunits, because the running time of a workunit is long (even for the short ones)

All of my GTX cards are overclock with different levels of success.

GTX 570
Voltage 1.1V
924MHz

GTX 570HD
Voltage 1.075V
881MHz

GTX 580
Voltage 1.138V
944MHz

GTX 580
Voltage 1.138V
953MHz

Now looking for a GTX 590!

____________
Thx - Paul

Note: Please don't use driver version 295 or 296! Recommended versions are 266 - 285.

Would be very helpful if ACEMD could flag "recoverable" errors in the Event Log. Would that be feasible? When a work unit takes longer than it was initially estimated to take, how can we know when to attribute that to recoverable errors rather than the many other variables that could be to blame? How reliable are those initial time estimates from GPUGrid?

How aware is the GPUGrid app of the hardware it is being run on? If a card's settings are changed, by the user or by the driver, in the middle of a WU, could that information be recorded by BOINC?

On the subject of downclocking - if overclocking tends to be energy inefficient, does downclocking ever improve energy efficiency? That might be a worthwhile area of study, especially if it means your PCs generate less heat and your A/C doesn't have to run 24/7.

Higher overclocking may work with lesser GPU utilizing workunits, but the highly GPU utilizing tasks may fail with those settings.
To make overclocking worth the effort, workunits should not fail at all. It's easy to loose the 10-15% gain of overclocking by failing workunits, because the running time of a workunit is long (even for the short ones)

On the subject of downclocking - if overclocking tends to be energy inefficient, does downclocking ever improve energy efficiency? That might be a worthwhile area of study, especially if it means your PCs generate less heat and your A/C doesn't have to run 24/7.

BTW: as a German I find the thought of crunching with private PCs in rooms with A/C quite strange. I already pay enough for the power consumption of the PCs, I wouldn't want to pay extra just to remove that heat. But we don't usually use A/Cs at home anyway.

MrS

EVGA GTX 590 @ 664MHZ standard memory clock. I will be pushing the memory clock a bit higher over the next few days.
____________
Thx - Paul

Note: Please don't use driver version 295 or 296! Recommended versions are 266 - 285.

I will be pushing the memory clock a bit higher over the next few days.

Thx for the insight on memory clocks and GPUGrid performance. I really did not want to spend hours today tuning memory clocks.
____________
Thx - Paul

Note: Please don't use driver version 295 or 296! Recommended versions are 266 - 285.

My GTX 580s are stable at 972MHz Core clock and 2000MHZ for memory with 1.138V. I want to go to 1,000MHZ but my initial attempt was a failure.

Has anyone used the new EVGA BIOS that unlocks the fans to 100% and raises the max voltage to 1.150? I think with 1.150V, I could get to 1GHz on my core clock.

What is the BIOS upgrade process? Has anyone had a BIOS upgrade fail? Does the card fall back to a default BIOS or is it an RMA issue?

Any help is appreciated.
____________
Thx - Paul

Note: Please don't use driver version 295 or 296! Recommended versions are 266 - 285.

It isn't worth the 3% gain. Better to wait to buy the big Kepler and then flash them. These are ebay cards so EVGA will likely not want to provide RMAs :-)

The new BIOS opens the fan to 100% and provides a max voltage of 1.150V Just enough to get to 1GHz!
____________
Thx - Paul

Note: Please don't use driver version 295 or 296! Recommended versions are 266 - 285.

MSI N580GTX

This card came clocked at 800 MHz out of the box a couple of weeks ago. It's much faster than my old MSI N460GTX Hawk. After running it awhile I bumped the GPU voltage up to 1.1v There's more overhead but I don't plan to go any farther. I started moving my GPU Clock Speed up in 5 MHz increments until about 855 MHZ and in 10 MHz increments above that number. I stopped at 900 MHz mostly because the GPU temp now hits around 70C and I find that to be the high end of my personal comfort range. It leaves me 27C of remaining temp. I can run any project I wish at 900 MHz, even Genefer which warns against overclocking. Other projects are SETI, PrimeGrid, Milkway and Einstein. So I am very happy with my new 580.

I have a question about what I find reported for some work units here. Here's what I found this morning. "# Number of cores" is being reported as 128 but the 580s have 512 cores in them. Is that an erroneous number or is that the number of cores being used? I was running an "MJHARVEY" workunit at the time. Regards, dave


Stderr output

<core_client_version>7.0.25</core_client_version>
<![CDATA[
<stderr_txt>
# Using device 0
# There is 1 device supporting CUDA
# Device 0: "GeForce GTX 580"
# Clock rate: 1.80 GHz
# Total amount of global memory: 1610285056 bytes
# Number of multiprocessors: 16
# Number of cores: 128
MDIO: cannot open file "restart.coor"
# Time per step (avg over 750000 steps): 12.343 ms
# Approximate elapsed time for entire WU: 9257.604 s
called boinc_finish

I flashed the BIOS on one of my 570s that was really hot ~82C. The fan will now go to 100% and this keeps the card in the 70s. I also added a couple of fans to help push air to the fan but it looks like a job for a new blower and some case modifications :-).

The BIOS flash is simple and takes about 2 min. to complete. If you have EVGA cards and they are running hot, use this new BIOS and open up the fans. The amount of cooling at 90% of the fan is far more than at 85%.

Keep Crunching!
____________
Thx - Paul

Note: Please don't use driver version 295 or 296! Recommended versions are 266 - 285.

GTX 670 w/ 301.42
Core@ 1249, Memory@ 3206

Win7 x64, BOINC 7.0.25, i7-920 @4.317

This card has completed 7 WUs across 3 different types so I think it's good.

IBUCH_5_affTRYP, MJHARVEY_MJHXA1, PAOLA_3EKO

When I have some more time I'll push it a bit harder but for now it is running smooth and cool (fan at 75% temp@50c).
____________
Thanks - Steve

GTX 670 w/ 301.42
Core@ 1249, Memory@ 3206

Win7 x64, BOINC 7.0.25, i7-920 @4.317

This card has completed 7 WUs across 3 different types so I think it's good.

IBUCH_5_affTRYP, MJHARVEY_MJHXA1, PAOLA_3EKO

When I have some more time I'll push it a bit harder but for now it is running smooth and cool (fan at 75% temp@50c).

Reporting in that on my GTX670 (301.42) w/OC of Core@ 1249, Memory@ 3206, BOINC 7.0.25, Win7x64 box I have been successfully running the new Long WUs (cuda 4.2) all day. Utilization is higher, power usage is up, WUs run very fast = big points for me and lots of nice results for the project!

3 NATHAN_RPS average a bit under 4 hours compared to my GTX480 @1556 shaders on cuda 3.1 app which was closer to 8 hrs. While I realize some of the improvement is the hardware and some is the new app (great job GPUGrid) ... seeing a 2x improvement makes me a happy guy.

Just for a laugh I looked the NATHAN 3.1 WUs on my GTX295 and those were almost 16 hrs :-)

So I guess I'm lucky that all my cards have plenty of stable OC headroom but that's why I buy good solid cards :-)

In the future I won't go dual GPU again (too hard to keep cool, fans must always be at 100%)
I probably won't go reference design either (not as tough as dual but can still be a challenge to cool)

What works for me is to research the card I am OCing to learn it's general characteristics and then figure which WUs at the time push our GPUs the most. Then I crank up the voltage until I can't keep the keep temps roughly at 75c or lower. Next comes upping the clocks as appropriate for the GPU model. Once I reach the OC limit I start stepping down the voltage until I find the sweet spot for the card I am working with!
____________
Thanks - Steve