EVGA OC Scanner X artifacting in SLI

[BuschyRedBeard]

Not sure what the problem is. I Have two EVGA 780 SC ACX's in SLI. I was having green pixels marching around on the left side of my monitor. It was only happening when computer first booted up and all the startup programs launched. Once it started it would only last for about 15 seconds. I started using different test programs and had no issues running everything but when I use EVGA's OC Scanner X and run it, regardless of test resolution, the image artifacts so bad you can't hardly see the image.

 

I unhooked the DVI-D cable both at the computer and the monitor and it still happens regardless of running SLI or not. It only ever happens on the Dell 30" and doesn't happen on my Samsung 17".

 

I've tried doing the same test on each individual card and have no problems. I even put in my old 560ti's and the exact same thing happens making me think it could be the PSU or the SLI Bridge. I don't want to just throw parts at it though. I have a decent PSU, though it is a few years old. In game, Valley and Heaven I have no issues at all.

 

 

Can anybody make any suggestions on how to move forward? The power supply is the Corsair TX850W.

Edited October 13, 2014 by BuschyRedBeard

[saunders1991]

I've seen pretty much the same issue with one my older builds, it ended up being the SLI bridge, you should try and get your hands on a cheap one from NCIX or something, I've even grabbed some on ebay. If possible go for the solid PCB bridges as they seem to be significantly more durable, but they are more expensive.

Depending on how old the PSU is, degradation could cause power delivery issues, I know my 2 780s pull about 800W from the wall, so 850W is kinda pushing it.

 

Overall, I would try getting a new sli bridge first, and if that doesn't fix the issue, new power supply is probably your best bet.

[saunders1991]

Quick thought, try with a single card installed, in either PCIE slot and see if the issue persists, if it only happens in one lane it might be a dying PCIE lane.

 

Edit. Nevermind, I forgot you have no issues with single card setup.

[BuschyRedBeard]

I've seen pretty much the same issue with one my older builds, it ended up being the SLI bridge, you should try and get your hands on a cheap one from NCIX or something, I've even grabbed some on ebay. If possible go for the solid PCB bridges as they seem to be significantly more durable, but they are more expensive.

Depending on how old the PSU is, degradation could cause power delivery issues, I know my 2 780s pull about 800W from the wall, so 850W is kinda pushing it.

 

Overall, I would try getting a new sli bridge first, and if that doesn't fix the issue, new power supply is probably your best bet.

Thanks for the response. Yeah I was thinking SLI bridge. I can't find the one that came with my motherboard and picked one up from Fry's. It is an Asus but that doesn't mean it isn't bad. I will start with that and go from there. Hopefully I don't need a new PSU but if I do I've been wanting a modular one.

 

Forced upgrades are OK I guess. I ran my old 560 tis in SLI and never had an issue. I live in a RV and I'm am wondering if maybe I'm just getting some dirty power. It is only at startup though so maybe the PSU is getting weak and is doing it while warming up?