ASUS & MSI Can't help. HAVE to underclock GPU.

[Tom72468]

2 MSI R6970 Lightnings....Have to underclock to 905 to not lock up under load. 2 cards, 2 motherboards, 2 PSU's. My question is can a motherboard damage 2 GPUs in exactly the same way, at exactly the same time? 1 6970 ran fine for 3 years, then crossfire 2 6970s and ran fine for 2 weeks, then I have to drop core to 905....Even on different computers. Clean install of windows, six different drivers, Corsair PSU's (750, & 850), New memory....Keep in mind...Everything worked fine for a while...ASUS & MSI don't have anyone who knows anything? 75W through PCI-E blows their mind....Did my motherboard (ASUS P6T-SE) do this??? And HOW!?! 2 cards, lock up @ 940 under load.... 1 card locks up @ 940 under load. Cards work fine @ 905. Different slots, MBs, CPUs, Memory, PSUs, different drivers...There is NO CONNECTION! Did my motherboard damage both cards in exactly the same way???

 

[cin19]

Corsair PSU's (750, & 850)

Which model ? Also what cpu do you have? do you oc the cpu too? I think the problem is from the PSU, or the GPU are overheat. Even you don't oc the CPU, you will need a good 800W PSU.

Also do you check the GPU temp too? If you have two monitors, you can open the software, like MSI afterburner, in other monitor to monitor the temp when you are gaming. When the PC does freeze, and check the temp right the way to see what temp you get. From what I read, if the temp is around 65C-85C, you are good.

By the way, usually the MB will not damage your GPU, only the temp is too high, or the GPU is old and has problem, or the PSU don't provide enough power to cause the PC lock up like that.

 

[Tom72468]

GPU temp: Never above 68º. CPU: Not OC'd, and temp never above 60º. Both GPU's were running fine with a Corsair 750W...Swapped to a Corsair 850W, & removed 1 card, then swapped cards, even swapped PCI-E slots. GPU still crashes under load @ 940 Core clock..But NOT 905. (BOTH CARDS CRASH EXACTLY THE SAME WAY w/ EXACTLY THE SAME TEMPS IN TWO DIFFERENT MOTHERBOARDS).

1st setup: ASUS P6T SE, i7 920 @ 2.67, 6GB Corsair DDR3 @ 1333, 850W Corsair PSU
2nd setup: ASUS P7P55-M, i3 550 @ 3.2, 8GB Crucial @ 1600, 750W Corsair PSU

 

[cin19]

1st setup: ASUS P6T SE, i7 920 @ 2.67, 6GB Corsair DDR3 @ 1333, 850W Corsair PSU
2nd setup: ASUS P7P55-M, i3 550 @ 3.2, 8GB Crucial @ 1600, 750W Corsair PSU

Is it the cx 750W? or tx 750W? or hxi? same as the 850W too.

If they are the CX series one you will need other PSU. Look at the cx 750 review here: http://www.hardocp.com/article/2015/01/21/corsair_cx750_750w_power_supply_review/9

 

[Tom72468]

1st setup: ASUS P6T SE, i7 920 @ 2.67, 6GB Corsair DDR3 @ 1333, 850W Corsair PSU
2nd setup: ASUS P7P55-M, i3 550 @ 3.2, 8GB Crucial @ 1600, 750W Corsair PSU

Is it the cx 750W? or tx 750W? or hxi? same as the 850W too.

If they are the CX series one you will need other PSU. Look at the cx 750 review here: http://www.hardocp.com/article/2015/01/21/corsair_cx750_750w_power_supply_review/9

 

[Tom72468]

It's a TX750 & a CX850M. 2 250W R6970's ran fine on the TX750. Now, 1 single card (Either one), will not run under load at 940 clock, but will at 905 with either the TX750, or the new, CX850. I sincerely doubt that a 35MHz clock speed difference in the GPU would cause both PSU's to faulter. Unless it's possible that the TX750 damaged both GPU's through the 2 8-pin power connectors....In exactly the same way. Please try to keep in mind that these are 2 separate, but identical cards, in two separate computers, swapped between the two computers, behaving the exact same way...While working fine for a couple of weeks...With no software, or hardware changes.

 

[cin19]

May try up the GPU voltage little bit by using the MSI afterburner or other software you used. I think the GPU don't run stable under the default voltage.

 

[Tom72468]

May try up the GPU voltage little bit by using the MSI afterburner or other software you used. I think the GPU don't run stable under the default voltage.

It did for 4 years. But yes...From 1.174 to 1.225v.