This is a bit of a hardware question, but I guess its on the right place here. If not a moderator may move it.
I built me a new rig last week and seeing a few things.
I had a 770 in an AMD fx8350 on a Sabertooth MOBO.
My new one has an i7 4471 on a Sabertooth MOBO as well (not the same type off course). And with the same WU's (if they are really the same) the 770 is around 3000 seconds faster on the Intel.

Secondly I put a GTX780Ti in as the primary GPU and this one is around 3000 seconds faster than the 770.

I installed all hardware and software from the box, did no tweaking and let it run. Checking with GPU-Z I saw that the 780Ti went quickly to 85-87°C, what I don't like so I used GPUTweak from Asus to make a change. I have set the GPU Temp Target to 75°C and left the Power Target to 100%. Did nothing with clock speeds. Set fan to user define and made that it run more. Now I see:

The 780Ti:
GPU Core CLock:966.6MHz
GPU Memory Clock: 1752.8MHz
Temperature: 75°C
GPU Load: 80-81%
Power Consumption: ~74%
PerfCap Reason: Limited by temperature limit (I understand as I set that)

The 770:
GPU Core Clock: 1045.2MHZ
GPU Memory Clock: 1752.8MHz
Temperature: 63°C
GPU Load: 94%
Power Consumption: ~69%
PerfCap Reason: Limited by reliability voltage (I don't understand)

The 780Ti is from Asus and has 1 fan, the 770 is also from Asus and has two fans.
When I set the temperature limit to 85°C, then the GPU load doesn't change but the card operates at 82-83°C.
Question: how can I get the 780Ti to operate around 90%? Or is ~80% its maximum with Santi WU's?

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Greetings from TJ

I think the clue is here:

PerfCap Reason: Limited by temperature limit (I understand as I set that)

If you get the temperature down to 70C or less the card will automatically boost the GPU Core clock rate?

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BOINC <<--- credit whores, pedants, alien hunters

"PerfCap Reason: Limited by reliability voltage"

Means the card has reached it's maximum allowed voltage for reliable operation, i.e. the top turbo boost bin, and won't go any higher. BTW: on GTX770 cards this is ~1.20 V, more than previous cards were allowed. At this voltage the card probably takes ~1.20 GHz instead of those "wimpy" 1.05 GHz. For comparison: my GK104 (same chip) reaches those 1.05 GHz at ~1.05 V.. which is incidently what I'm running it at. Far more efficent than 1.20 V.

Regarding your 780Ti: as Dagorath said if you increase the fan speed even more and lower the temperature, the card will boost higher (and use a less efficient voltage to get there, of course). However, this will not increase GPU utilization, as it's already in % and always refers to the current clock speed, not some fantasy value. I.e. if the GPU is bottlenecked somewhere GPU utilization will even drop at higher clock speeds, because there simply won'T be enough work to do for the cores.

I don't know what's holding your card back. You could stop any other work te CPU might be doing and test if this help significantly. You could scale the power limit back and watch the results: at lower clock speeds GPU utilization should increase, while efficiency will go up (until you reach the base clock & voltage). You could overclock your GPU memory and see if this helps. The cards are said to take almost 2000 MHz, but overclocking is an obvious risk. You could also try to run 2 concurrent tasks - maybe this GPu is finally large enough to benefit from this with more than SRs. Although this might change as soon as you get some Nathan-kicks.

MrS

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Scanning for our furry friends since Jan 2002

...The cards are said to take almost 2000 MHz, but overclocking is an obvious risk.

What cards are you referring to? 100% overclock is a bit steep.

The GPU Memory clock is 7012MHz. This is (was) standard I did not touch that setting at all. Is that okay?
I have now set the fan higher and the GPU Temp Target to 69°C, to see it that works. Currently still at 81% GPU Usage.

Tried already to stop all CPU tasks, but didn't help. Now only 4 WU's (Docking) are running on the CPU.

The PC is now running for 3 days and 7 hours. The graphics of Asus GPUTweak are no gone, empty, only the grid. But the values at the right side change. Is this normal of a bug from Asus?

Let it run overnight and look in the morning again.

Thanks so far.

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Greetings from TJ

Letting the 780Ti run overnight at 69°C resulted in an GPU load of 82-83% but the GPU Core Clock went to 885MHz.
I have now set maximum temperature to 70°C and GPU Core Clock is running at 901.4MHz, with GPU Load of 81% steady. Perhaps this 81-83% is the maximum for this card for Santi's as ETA suggested.
The VDDC is 1.0250V for the 780Ti and 1.160V for the 770 according to GPU-Z. Do I need to change anything there?

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Greetings from TJ

Something is hindering the performance of your GTX 780 Ti. I guess that it's the Win7 WDDM overhead.
For comparison:
I163-SANTI_bax2-6-32-RND6602_0 24460s (6h48m) (your Win7 host)
I203-SANTI_bax2-4-32-RND8709_0 16905s (4h42m) (my WinXP host)
These are not some specially selected running times, I have similar running times for this kind of WU on my host, and you have similar running times on yours (so I'm not comparing my best running time to your worst.) According to these numbers, my GTX 780 Ti is 44,7% faster under WinXP (6 SIMAP CPU tasks are running) than yours under Win7. (our CPUs are almost the same, as I have an i7-4770k@3.5GHz)
My GTX 780 Ti is running at 1110 MHz, temp: 65°C, GPU load: 96%, VDDC: 1.15-1.20V, Memory controller load: 26%, (while crunching 167x-SANTI_MAR423cap310-1-32-RND5480_1)

Thanks for your replay Zoltan.
Indeed I have checked my times with other 780Ti's and that is why I started this thread. My 770 is almost as fast as the 780Ti and that can't be.

You have you card way cooler running then I. Can you please advise me what I need to change? What program are you using to alter the settings?

What is the Win7 WDDM overhead? And if, how can I change that?

Your replay is highly appreciated as always.

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Greetings from TJ

You have you card way cooler running then I. Can you please advise me what I need to change? What program are you using to alter the settings?

I'm using MSI Afterburner, with user defined fan control (30°C 40% fan speed to 80°C 100% fan speed) the fan speed is 85% at the moment (and it's noisy a bit), but this configuration is caseless :)

What is the Win7 WDDM overhead?

This is the Windows Display Driver Model introduced with Windows Vista. It's a more secure way to access the display's hardware (a display hardware/software failure won't bring the whole OS down), but at the same time it's slower - hence the overhead. (as far as I understand it)

And if, how can I change that?

You can't turn it off. You can change it only by using a different OS (Linux, WinXP). That's why I'm still using WinXPx64. It will be quite exciting after April 2014, since WinXP's extended support period will expire then - so there won't be more hotfixes for WinXP (and Win.Server 2003) from MS after that.

I think this WDDM overhead could impact faster cards more than slower cards, as a faster card will complete a piece of calculation faster, but the WDDM overhead of every interaction with the OS takes the same time either for a slower or faster GPU, and the number of interactions is (almost) the same for every GPU (slower or faster) while crunching a given WU. So for example the total time of the calculations on the GPU is X, and the WDDM overhead is Y, then the total running time is X+Y. If you use a twice as fast GPU, the total time of the calculations will be X/2, but the WDDM overhead stays Y, so the total running time will be X/2+Y. If the X/Y ratio is high, the total running time won't be affected by Y too much, so the running time could be reduced (almost) in direct proportion by using a faster GPU, but I'm afraid, that the GTX 780 Ti (and the GTX 770) is too fast, so the X/Y ratio is not high enough to have linear decrease in the running times (on Win7) by using a faster card. The Maxwell chips will have their own dedicated ARM CPU on chip to eliminate this bottleneck.

At the moment I have a fan speed of 82% and 70°C with Asus GPU Tweak.

When using MSI Afterburner I can not find my second card to alter things.

If I go for default setting, the GPU Boost Clock displays 982 MHZ but operates at 876 MHZ, the temperature goes to 82°C and fan duty to 60%.
GPU Load stays at 81%. So the default is not helping me.

Do you have a second card in this system Zoltan?
As I have the 780Ti in the first slot and the 770 in the second. There is about 2 centimeters room in between. The 770 (with two fans, stays cool at 61°C.

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Greetings from TJ

Just a notice.
I was my cards a bit tweaking, core clock little higher to 1045MHz (not nown if related) but all of a sudden screens went black and system boots,, with message Windows didn't close correctly.
Checked with WhoCrashed and it was a Bad Pool Header from nVidia Windows kernel driver 331.82.
After boot and everything running again, one Noelia (was 98% before crash) finished correctly, the other a Santi was 54% done, not as it started new again.

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Greetings from TJ

Do you have a second card in this system Zoltan?

Yes I have a GTX 670 in the farthest PCIe slot (it runs at PICe2.0 x4, but the GTX 780 Ti runs at PCIe3.0 x16).

As I have the 780Ti in the first slot and the 770 in the second. There is about 2 centimeters room in between. The 770 (with two fans, stays cool at 61°C.

There is 4 slot space between the back of the GTX 670 and the "glass" of the GTX 780 Ti's cooler. It's about 9 centimeters.

Just a notice.
I was my cards a bit tweaking, core clock little higher to 1045MHz (not nown if related) but all of a sudden screens went black and system boots,, with message Windows didn't close correctly.
Checked with WhoCrashed and it was a Bad Pool Header from nVidia Windows kernel driver 331.82.
After boot and everything running again, one Noelia (was 98% before crash) finished correctly, the other a Santi was 54% done, not as it started new again.

So much for the WDDM is crash free.

I have nothing changed at the 770, but set the voltage of the 780Ti to 1.175mV and the Boost Clock to 1110MHz. The Power Target still at 100% and the Temp Target to 70°C and let it run overnight.

According to GPU-Z the Core Clock is running at 875.7MHz, the GPU load is ~78% and Power Consumption is 57.8%. The temperature is 67°C (which I like). The PerfCap Reason is now GPU utilization.
It does now LR's in less than 7 hours. So it made a good contribution to the project.
Could it be better, if I give it little more voltage and set the core clock lower or have I already screwed up the settings?

GPU-Z has more sensors for the 770, 4 about voltage, and 1 of VRM Temperature.
I don't see this with the 780Ti and the 660. Is the 770 special?

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Greetings from TJ

There is 4 slot space between the back of the GTX 670 and the "glass" of the GTX 780 Ti's cooler. It's about 9 centimeters.

That is good, but you have another MOBO than I have, and I wouldn't listen to you :)
Well I am already saving for a Maxwell and will put that in a new system with a Gigabyte MOBO.

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Greetings from TJ

I have made the settings of the 780Ti the same as for the 770 but the clock stays operating at 875MHz.

Finally I got a Noelia on the 780Ti and now the GPU load is 91%, while on the Santi's it is ~80% but also with the Noelia the clock stays 875MHz.

Mostly Zoltan has good advise but as he runs XP, he has a more capable OS then I with Win7. Perhaps someone with Win7 and a 780Ti can help me or give some more info to steer the 780Ti to a higher GPU load on other tasks than Noelia's or perhaps it is not possible with a 780Ti and is the "to fast" for Windows?

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Greetings from TJ

Hello Zoltan,

I have found how I get my cards BIOS into the Kepler BIOS Tweaker.
If you have time (as your own problem is sort out) would you please:
1. let me know which values you have changed?
2. how then get the new cards BIOS into the card?

Thanks for you help as always.

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Greetings from TJ

Hi TJ!

I have found how I get my cards BIOS into the Kepler BIOS Tweaker.
If you have time (as your own problem is sort out) would you please:
1. let me know which values you have changed?

I've changed everything :)
Tell me what do you want to achieve, and I'll try to be more specific :).
There are non documented settings for example some fields on the "boost states" and on the "clock states" tab.
If you want to increase the stability of your card, you should try to increase the voltage by 12mV steps, and/or the power target. The percentages shown will change beside the power values, as you change them. The power values are in miliwatts, (it's quite pointless for the high-end cards) so you can forget the last thre zeroes, as you can change it only by 1000mW (=1W) steps.
Or you can lower the boost clock ("Common" tab) and on the P0 and P2 states (Boost states tab).
I suggest to change only one stetting at a time, and keep the original BIOS.

2. how then get the new cards BIOS into the card?

1. For practical reasons, you should put nvflash.exe (plus nvflsh32.sys and nvflsh64.sys) to the same folder where the (modded) bios is located.
2. Open an administrative command prompt.
3. Go to the folder where the (modded) BIOS file is stored. (for exapmple: cd \\keplerbiostewaker)
4. If you have more than one card in the system, you should check which one is to flash with the command: nvflash -a
5. Use nvflash.exe to flash the BIOS to the card: nvflash mybios.rom
6. If you have more than one card in the system, you should add an "--index=n" switch to the command line, specifying the number of the card you got in step 4. nvflash --index=1 mybios.rom (you have to check hex numbers of vendor ID, product ID, subvendor ID, PCI subsystem ID, or PCI bus number, so it's much easier if you have only one card in the system)
7. If the BIOS update is successful, you should restart your system.

Thank you Zoltan.

I have changed all settings too with MSI Afterburner, GPU Tweak (from Asus) and EVGA Precision X.
I thought the 780Ti would be a lot faster then a GTX 770, but it is only ~3000 seconds faster, on Win7.
Your card is about 7000 seconds faster then mine due to XP.

What I would like to achieve is to be that the 780Ti is a bit faster. I will try Linux but don't have not a lot of confidence yet.

If you have some tips/idea's I could try. I would be grateful.

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Greetings from TJ