SLI and GPU OC headroom

[Rocketdog2112]

Just to comment and ask a question on an interesting observation... First off, let me start out by stating I know SLI is dead, blah... blah... blah. OK, now that we have that out of the way...

I run two GTX 980 gpu's in SLI on a X58 motherboard with a always stable heavy overclock using MSI Afterburner.

Yesterday after much debate with myself, I decided to pull one of the cards and leave SLI behind to see if it did indeed increase gaming performance as claimed by many.

I reloaded the gpu drivers and a check of the Nvidia Control Panel indicated the graphics were only running a single card.

The only item i did not reset was the Afterburner OC settings.

Fired up a game and instant video crash. WTF?

I had to completely reset Afterburner to stock profile and start back working on the overclock. I was not able to get anywhere near the overclock i originally had in SLI.

So, question is... Does SLI increase GPU overclock headroom or am i missing something here?

[Skiiwee29]

No, if anything, you have less OC headroom with SLI as you're limited by the slower/worst of the 2 cards and what it can do. 

[Mick Naughty]

Yea the setup will run as low as the slowest card. 

But also, if the cards arent being utilized 99% they may boost higher as each card isnt working hard.

Had one card boost 300hz higher than the other as the cards only ran around 50/60% as I used a frame cap.

But they were also hard clocked and had an oc applied.

So if you did the initial oc with both cards installed and only stressed them in a game where the cpu couldn't keep up, maybe it was only stable for that reason.

[jaslion]

No it's the opposite. Sli is limited by the slowest card so it could be that the card that is in there is just a very finicky ocer and the other card is the better one.

[Kilrah]

I'd guess that the cards were never under enough of a load to show problems becasue of the "waiting for the other card" caused by SLI...