I believe mfaktc has very little gpu memory usage. CuLu, however does of course.

[QUOTE=kracker;334597]I believe mfaktc has very little gpu memory usage. CuLu, however does of course.[/QUOTE]

Quite. If you're running only mfaktc, memory clock will have little to no impact on performance. If you run CuLu, memory clock should scale mostly linearly with performance (up to some upper limit that's probably out of reach -- be sure your card is absolutely stable with at least a few double checks).

[QUOTE=Xyzzy;334596]We have been messing around with the extremely confusing "[URL="http://www.evga.com/precision/"]EVGA Precision X[/URL]" software. There are so many options it is ridiculous!

Anyways, we were messing with the memory clock setting. By default on our GTX690 it is 1502.3MHz. We lowered this to 1252.8MHz and the performance did not change!

The temperatures and voltages do not change, either.

Does this make sense?

Would running the memory slower like that make it less likely to have a flipped bit?

FWIW, the GPU clock is 1058.2MHz. The performance changes a lot when we mess around with that!

:mike:[/QUOTE]

I had my memory clock cranked way down on the 580 and it made no noticeable change on the performance or temperature.

running MF , the performance should scale linear with GPU-clock


gpu clock * gpufactor = Ghz-d/Day

ex.

966mhz *x = 439
x = 0,454

1241mhz * 0,454 = ?

*proven*

Is there any way to disable the "simple selftest" on startup? Maybe just run it once for each version of mfaktc or once per month? It wastes time that it could spend crunching when you switch stop and start it often, e.g. [URL="http://www.mersenneforum.org/showthread.php?t=18088"]to switch speeds[/URL].

Without changing some code and recompile or binary hacking: no, not possible.
And there is (at least) one broken driver version available in the wild so I don't recommend to do so. How much time does it really take on your system?

Oliver

[QUOTE=TheJudger;337056]Without changing some code and recompile or binary hacking: no, not possible.
And there is (at least) one broken driver version available in the wild so I don't recommend to do so. How much time does it really take on your system?

Oliver[/QUOTE]

About 6-7 seconds. It seems longer when using my controller app because it doesn't show the output until mfaktc finishes the first class (first time it senses a newline, I suppose) which means it looks like closer to 18 seconds on my current GPU/assignment.
I was under the impression that it really only was meant to test mfaktc's internals, but the fact that it can detect a broken driver makes it more useful.
I guess it's really not as bad as I thought, all things considered. I wouldn't expect most people to spend more than about a minute (~10 runs) per day running the selftest, really a trivial amount.
Thanks for the info.

Odd, I don't run that selftest more than once every few days. Do you turn the program off and on a lot?

[QUOTE=Aramis Wyler;337143]Odd, I don't run that selftest more than once every few days. Do you turn the program off and on a lot?[/QUOTE]

Yes, as part of switching speeds using my [URL="http://www.mersenneforum.org/showthread.php?t=18088"]MfaktX Controller[/URL] tool. Mfaktc doesn't support a nicer way of switching the GPUSieveSize, so the tool stops mfaktc, changes the ini file, and then starts it again. Due to the selftest, there's a few seconds of lost time each time you do this. I have the tool set up to switch automatically when the screensaver goes off or on, and there's a PauseWhileRunning feature, and you can change it any time you want, so it can happen a number of times per day - but at 6-7 seconds per, it's not a significant loss.

Okay, I have questions that have probably been asked time and time again: what is the minimum exponent that can be tested with mfaktc 0.20? What is the minimum bit depth? Maximum? Is there a maximum exponent testable by design, or just based on memory?
Thanks in advance!

If memory serve, smallest expo is 1M, maximum 2^32-1 (or was it 2^31-1?), following that, minimum depth should be 20, and maximum... well.. 2^31-1?