[Kiros]

So I finally came to a decision and returned the Titan Xp and bought 2x 1080ti FE from Nvidia. Now I never had this issue until I put in these cards but when both cards are at 100% load the PC will eventually/randomly cut power and then restart. It'll happen much quicker or instantly if I set the power limit on the cards above 100%+ Initially I thought my power supply, Seasonic Silent Snow 1050W was starting to go bad since I have had it for 1.5 years but I've never broke 800 watts usage until last month after I installed these cards

So what I have done so far is I purchased another of the same model Seasonic Silent Snow 1050w.. Apparently the power cutting off still occurred even with the new unit so my PSU is definitely not failing. Then I started wonder if it was my motherboard so I went and got a temporary one, Asus X99 Strix ROG. Apparently its not that either and I may have wasted my time RMAing my gigabyte motherboard thinking the VRMs were overheating.

I even went to thinking it was the PCI-e 6 and 8 pins power cables and pulled new cables from another seasonic PSU I was going to give to a friend. Problem still persists. Now I'm down to thinking it might be the new GPUs being faulty but just an hour ago I came across a couple nvidia.com threads through a google search on 980 Ti SLI having a similar issue. So I'm curious if it has to do with my PSU being a single 12v rail not being able to handle the stress? No power cutting off if I run one card at max

I also currently run my CPU at 4.2 @ 1.235v and both GPUs are watercooled

 

[TwoCables]

How exactly do you have the cards connected to the PSU?

 

[Kiros]

I'm just using what the PSU came with, its the 8+8pin wire along with sleeved extenders for aesthetics. But I think I figured out what's wrong with my rig now. I couldn't believe it at first but apparently 1050Watts isn't enough! I was just stressing both my CPU and GPUs while keeping an eye on my kill-a-watt meter this time and surely enough when I was moving the power target slide 105%-110% with everything being stressed puts my rig at 1000 watts usage for a split second before it shut off.

 

[TwoCables]

Quote:

Originally Posted by Kiros

I'm just using what the PSU came with, its the 8+8pin wire along with sleeved extenders for aesthetics. But I think I figured out what's wrong with my rig now. I couldn't believe it at first but apparently 1050Watts isn't enough! I was just stressing both my CPU and GPUs while keeping an eye on my kill-a-watt meter this time and surely enough when I was moving the power target slide 105%-110% with everything being stressed puts my rig at 1000 watts usage for a split second before it shut off.

You need to dedicate 1 x PCI-E cable per video card. If you have 1 cable with 4 connectors, you're overdoing it. You need 2 separate cables. 1000W at the wall is nothing for this PSU. That's still only ~900W, which should be a cakewalk for it.

 

[shilka]

The Seasonic PSU you bought is a multi rail PSU so if its shutting off you are overloading one or more of the rails
You dont need more wattage you need to spread the load out over more rails

And yes some Seasonic units are multi rail even if they are branded and sold as single rail
If you got 1000 watts from the kill a wattage you need to remember to take the efficiency off which means you are using around 900 watts

You are not overloading the PSU itself you are overloading one or more of the 12v rails