Quote from: gfgrimm on March 05, 2014, 10:17:30 AM

Quote from: jstabb on March 05, 2014, 10:00:37 AM

Quote from: gfgrimm on March 05, 2014, 08:59:38 AM

Quote from: ithd on March 05, 2014, 07:18:29 AM

My 5x 750 ti rig is giving me huge headaches. Sad

I'm running all 5 on powered risers and 6 pin connectors on a 750W RM corsair PSU. Asrock h81 btc pro mobo. 8gb RAM. Latest Nvidia drivers.

Is anyone getting huge lag/computer freezes when running multiple 750 Tis (5+) in one instance? I'm running windows 8.1 64 bit, and starting up all 5 at once freezes the PC (sometimes it's huge lag, sometimes I need to reboot, sometimes cudaminer crashes). Seems to only work with regular scrypt without freezing/crashing 100% of the time. I get 250 khs/card mining LTC at stock. I'm about to switch to Windows 7 to see if that changes anything.

If i don't use autotune, TDP usage seems to be pretty low (~850 khs for 5 cards), config: -l T5x24 -C 1 -H 0 -i 0
W/ autotune, I get low 80% TDP. 99% GPU usage.

Also any bit of OC to my cards (EVGA 750 ti ftw) seems to crash cudaminer about 10+ mins later (even "low" ones of +20 core, +200 mem). I don't know how other people seem to get huge clocks with these cards..

Any help would be greatly appreciated. Will throw 10 VTC anyone who can get me up and running stable at ~300+khs/card... Feel free to PM. Thanks!

I suspect that the Nvidia driver for W8.1x64 has a bug because I have 6x750 Ti's and I ran into the exact same thing.

Swap over to W7x64 and use settings: -l T5x24 -H2 -i 0 -C 1 -m 1
...I haven't really seen much difference between -m1 and no flag at all.

Use the x86 version of cudaminer when doing this on W7x64.

Finally, for whatever reason, Chrome running in the background with some Flash or HTML5 app (e.g. YouTube) gives a small boost.

Now you're good to go.

I really wanted this to work on W8.1x64 as well, but I think between MSFT/Nvidia/Cudaminer status quo, we're stuck with W7x64 for more than 2 cards running simultaneously.

Interesting. I have (3) GTX 750Ti and (1) GTX 780Ti on W8.1x64 and have not seen any issues. What motherboard are you running? Maybe it's a chipset driver issue rather than video card (my Win8.1 machine is on an old Asus P6T Deluxe for the record).

For me, I did not see much stability issues until I pushed it beyond four cards. But there was definitely overhead noticed on the aggregate hash rate I was getting with four cards. I'm on Z87-Pro w/ Intel Core-i5 2670k. Latest drivers, etc.

Thanks for the responses! I'm going to try installing W7x64 tonight and I'll let you guys know from there. Also, any good vertcoin settings for these cards?