GTX 970 SLI PC shutting off then turning back on

Hi

Just bought another 970 for sli and now my pc is shutting down and turning back on after like 5min of gaming, I'm running 2 different 970's one is Gigabyte windforce, Galax OC black edition, and i have a 750watt PSU, I'm trying to figure out if its the PSU or the two different 970's. Been searching on the net about recommended PSU and getting different answer some say minimum 800 others say 700 to 750. I have been running 2 670's fine on my old GPU's?

Try running your new 970 by itself in the system to eliminate it as the cause. If it works fine by itself, it is possible that your PSU may be failing now that it is pumping out a little more juice. 750W is adequate for 970 SLI though.

@BassMan: Its a thermaltake smart 750W don't know if that's any good or not

The card works fine by itself. Would i have to like manually down clock one card to match the other one. When I using 670's in triple monitor if I connected all monitors to one card it would only work on a single GPU but If I connect two monitors to the first card and the other monitor to the other card it would use both GPU's but with the 970's it wont let me I have to connect all monitors to one card.

@awax187187: It is best to sync the clocks on both GPUs. Also, don't OC more than what the weakest card is capable of. Try running them at the stock speed of the lowest factory clocked card and see if your system is stable. Also, double check that both cards are seated properly on your mobo and that all power cables are fully plugged in (I know, noob suggestion).

You could run 970 SLI with 500Watts PSU, check out if you've got problems with single GPU, switch between them, it might be the new card, it also might be the MOBO slot.

If you've got the same MOBO and the same PSU and you've ran 670s on them then it's probably the new card.

EDIT: try running SLI config with only 1 monitor for a while, let me know what happens.

@PredatorRules: OK runs fine using new single GPU. Enable sli again single monitor all ok, I tried triple monitor setup but soon as I alt tab back to windows the pc shuts off and restarts. By the way I am running Windows 10.

I think it might be windows 10 issue been searching around the web seems to be the problem, Iv never had windows 10 when I had sli 670

Well got issue with Wildstar speaking of Windows 10 related problems.

Not sure if it's Windows problem or not, you said it worked well with 1 monitor with SLI, try connecting all of the monitors to single GPU.

Yeah, try connecting all of the monitors to your "top" GPU.

How long did you test new card for? Play at least an hour to make sure it doesn't crash.

Did reinstall the drivers? Use DDU to uninstall the drivers and then install new ones (or reinstall the ones you were using).

ok so after all the testing and like over 6hours of fiddling around iv put it down to it being different brands of 970's just going to have to sell the galax and get another Gigabyte 970.

Not sure how different brands should make crashes, both should work automatically on the lowest brands' clocks.

@PredatorRules: its only thing I can think of, iv been playing for ages with the new galax on triple monitor for ages been able to alt tab in and out of games with out it crashing. Another weird thing as well when I sli 970 youtube videos don't work and now assetto corsa wont even work anymore also It wont recognise my HDMI audio to my amp but soon as I remove one of the cards from my pc everything works fine.

Zotac 970's do not allow SLI with different brands. I haven't heard anything about Galax or Gigabyte.

How old is the psu? That could be a factor.

The 970's should require less power than your 670's so the PSU shouldn't be the culprit. Connected all monitors to the top GPU? Re-installed drivers?

Does the BIOS in the GPU's have to be the same because they are different? also does the automatic down clocking of the cards only happen when your playing games because when I check it in windows one is higher then the other?

BIOS doesn't have to be the same and you have to manually downclock the other card yourself through Afterburner / Precision X or whatever software you are using.

My SLI setup isn't down clocking the faster card to the lowest card its doing the exact opposite, which makes me wonder why some games are causing my pc to shut down still. Even when I used afterburning I down clock the faster card but it actually doesn't down clock, its still overclocking to meet the other cards specs.

In that case use DDU to uninstall GPU drivers, reboot and reinstall the drivers (or install new ones). Make sure your Crossfire profile is turned off while you're doing that.

Also, uninstall Afterburner, reboot and reinstall it.

See if it works afterwards.

Still the same, iv ordered a new Seasonic PSU try that when it arrives

I know this is a week late, but yeah, new psu. Most efficiency is found at 50 percent psu load (so a 500w system runs most effeciently on a 1000w psu)

Hope it all worked out.

Just an update is was the PSU.