I have 2 quasi hosed memory sticks. The desktop I built in 2009 works intermittently. It feels like I've been fighting overheating battles most of the time.
I'm suspicious that the RAM went bad from heat from the gpu, and I'm trying to decide whether to just replace the RAM, or the graphics card as well. I briefly thought about starting from mobo, but life is too hectic right now.
*Danged if I can remember the details on the RAM right now, and I can't remember get into the system to check. I'll edit post when I know. It's 2 x 2GB, and has built-in heatsync. Has a name to identify the line...
So thoughts on just replacing RAM vs. upgrading the GPU that'll work with mobo but run cooler?
Really depends if you are a gamer or not, and what you like play if you do like videogames.
I would upgrade that old mobo to an asus crosshair iv am3+ or better, and get a 1090t or better, and move up to 8gb of ddr3 1666(having a mere 4gb could cause chugging on crossfire just by itself). the 2x 4850s might last a little bit longer, unless you really like bf3 and ArmA 2, games that are very demanding. For a cheaper upgrade get 2 6870s or a single 6970/6950/1-2gb. If you are running eyefinity, go for the 6900 series 1 OR 2GB, perhaps even for eyefinity. Bulldozer sounds sort of like a different kind of Bull at least until windows 8 is mainstream which might also be bull(****), so it's always a good idea to wait too.
Note: I have done almost zero research on your current setup. this is what I would do if I owned this setup so before you do anything just do your own research too. I would probably keep the old video cards and do the final video phase a little later on when 6970 matches today's 6870 price, and by that time there will be cheaper 7000 series cards which are the eyefinity gamer's dream come true(multiple mix/match monitor sizes/positions/resolutions, with bezel compensation for each monitor transition). Just my 2 cents.