Ok so as most of you know I have been posting alot about my 4830's in crossfire, and this issue has been around for awhile.
First let me show you my setup.
Processor: Phenom II 720 x3 OC from 2.8 ghz to 3.2 ghz stable prime 95 for 12 hours
MotherBoard: asrock A780GXE
VideoCard(s) two 4830's OC 575/685 core, 900/960 mhz memory
PowerSupply: Cooler master real power pro 750W
Memory: 4GB DDR2 1066 mhz
Ok, so if I play crysis for more then an hour or so my fps will drop dramatically, some times it happens some times it doesn't. I normally get 40+ fps and when it drops I get as low as 15-20 fps. if I leave the server and the rejoin my fps is fine again, for an hour or two. (only happens some times)
I haven't really played any other game this long, and all the other games for the amount of time I do play them never have a problem.
I am using the latest drivers, highest temp I have seen while gaming is 59C
OK I don't know why it's doing this but I always thought my temps never went above 59C but recently I seen it go up to 79C and the screen started flashing randomly like it's artifacting.
The bottom card never went past 50C underload but the top card get's way hot now (it didn't used to get this hot?!?)
So this is what I did, I switched the top card to the bottom and the bottom to the top. now the top card never goes past 70C but I see it in the 60's all the time. and I don't see any flashes but I still get lag during long periods of game play.
Why are my temps now so much higher then before? I even added a extra fan.
Maybe dust.... also some of the cards come with some cheap thermal paste that get less efficient with time. I would suggest you to get some Artic Silver 2 and take the heatsinks off on both of the cards, dust them off, remove all of the old paste from the GPU and the heatsink, apply some Artic Sliver 2 to the GPU and the heatsink, putt the heatsink back on the GPu and run the games again.
I can bet you will see a temperature difference...