This happened when I installed the new 306.23 drivers (I was using the beta 306.02 or something before them with no issues,) but I have tested multiple different drivers since then with no improvements.
I started to notice severe slowdown issues in GW2, after loading screens my framerate would just get worse and worse. I also started noticing issues on my right hand monitor, the monitor driven from card 2. (I've got a surround setup)
I then decided to take a look at the cards, reseat them, nothing seemed out of the ordinary. Now, the secondary card is my slightly older card, which I have had running at 900/1800/2000 before at 1.1v. This is a good card, and I used it for 12 months without issue.
I started running some tests on each card, and overclocking etc. This is what I found;
When running in SLI (I was using FurMark for the tests) Card1 was running at 1.001v and at 98-100% load. Card2 was running at 0.988v and sometimes was only running at 50% load. This looked worrying - when I tested both cards 2 months ago when I installed SLI it was 98-100 for both of them.
I then decided to test the card by itsself, and it hit 100% usage no problem. No issues on a 1hr long FurMark burn test at all. Exactly the same framerates as Card1 solo.
I then tried overclocking to see what the cards limits were, and to see if it would make any difference. I found something straight away - Card2 wouldn't clock over 0.988v. I could overvolt the other one (Using EVGA Precision X - Not MSI Afterburner (I had some issues with it a while ago - can't remember what but it made some games unplayable)) but Card2 would not overvolt. Both have an updated firmware for the fan unlock from the EVGA site.
Now, they both hit 850/1700/2000 no problem, but still Card2 wouldn't use more than about 50-70% load. This was giving me lower framerates than just using a single card, so there was obviously something wrong.
And this is where I need help. I'm out of ideas and I don't know what to do. By itsself, Card2 is absolutely fine by itsself, except for the fact that it won't overvolt. I'll test Afterburner in a second, but even before I started overclocking it seemed to have a lower voltage.
What can I do? What would the problem be?
Did you link the cards when using evga precision so settings for one would be for the other.
Yes, Afterburner seems to be working for me now though.
Also, I solved the heat problem - Swapping the cards around did the job. The Dual Fan one actually runs about 5c hotter, so I put the other card as the master and now it's dropped by 10c and the other one has gone up by 5c