[QUOTE=flashjh;354372]I can only speak for GTX 580 but it's not too hard to make changes to the number and see what you get.[/QUOTE]

For sure. Thanks for mentioning it. I never messed with that value, though I did with others.

[QUOTE=flashjh;354357]What is your GPUSievePrimes set to? I get best results with (GTX 580):

GPUSievePrimes=70000
GPUSieveSize=128
GPUSieveProcessSize=16[/QUOTE]

I see no difference if set to the default, 50000, 70000, or 100000.

I think it would be useful if mfaktc had an "auto-configure" feature that tries different parameters and determines the best configuration.

I end up with 30K for the 570, and 65K for the 580. The difference is still slight, but more pronounced on the 570.

Indeed. I'm not going to remote in to test the differences, and I think tweaking between 30K -100K gives no more than 5 or 10 GHzDays/Day per card, but when you're pushing the systems as hard as you can, everything counts.

[QUOTE=Mark Rose;354383]I see no difference if set to the default, 50000, 70000, or 100000.[/QUOTE]

Okay, I take that back. After playing with the values for a while, when factoring a 72 Mbit or 74 Mbit number, these are the best values for both the GTX 760 (260 GHz-d/day) and the GT 430 (50 GHz-d/day):

GPUSievePrimes=100000
GPUSieveSize=128
GPUSieveProcessSize=8

[QUOTE=Mark Rose;354927]GPUSievePrimes=100000
GPUSieveSize=128
GPUSieveProcessSize=8[/QUOTE]I agree that gives good performance, but a high GPUSieveSize kills my GUI experience -- there is significant lag just minimizing a window for example, and forget about playing a video or a game. I find GPUSieveSize=32 to be acceptable, although still not completely unnoticed.

The systems that I do TF on are mostly for TF. When we want to play a game or use it for something else we just stop the TF temporarily.

I'm mostly doing low TF (up to 2^64) in the [url=http://www.mersenne.ca/tf1G.php]1G+ range[/url], which necessitates CPU sieving and 4+ instances of mfaktc, but is utterly transparent to whatever else wants to use the GPU.

[QUOTE=James Heinrich;354933]I agree that gives good performance, but a high GPUSieveSize kills my GUI experience -- there is significant lag just minimizing a window for example, and forget about playing a video or a game. I find GPUSieveSize=32 to be acceptable, although still not completely unnoticed.[/QUOTE]

Yeah, I just stop the factoring when I'm actually using the system with the GTX 760. Things like watching videos and scrolling are too slow.

My GT 430's are not used for displays at all, so they can keep factoring away :)

[QUOTE=James Heinrich;354941]I'm mostly doing low TF (up to 2^64) in the [url=http://www.mersenne.ca/tf1G.php]1G+ range[/url], which necessitates CPU sieving and 4+ instances of mfaktc, but is utterly transparent to whatever else wants to use the GPU.[/QUOTE]

I did a bunch of that earlier. I noticed the mersenne.ca stats for it are extremely slow to update though :/

[QUOTE=James Heinrich;354941]I'm mostly doing low TF (up to 2^64) in the [URL="http://www.mersenne.ca/tf1G.php"]1G+ range[/URL], which necessitates CPU sieving and 4+ instances of mfaktc, but is utterly transparent to whatever else wants to use the GPU.[/QUOTE]

But isn't that a rather inefficient use of GPUs? I suspect nothing beats old Athlons at TF under 64 bit.