I have XFX 290 core edition with accelero xtreme iv, unlocked to 290X temps : max gpu:60 vrm:65 GPU overclocking is fine, i can max out 1150 +75mv with afterburner. Memory overclocking is the problem, no matter how much I overclock my memory i got black screen after 5-10 min of gameplay. memory is Elpida. It is not psu problem i'm sure. Can this be fixed, another bios maybe, or something else....? Even when memory is on stock 1250 sometimes i get black screen after 1h of gameplay....
Might just be faulty memory. By flashing the bios you most likely did break the warranty, that is if they find out during the RMA process.
Flip the BIOS switch to revert the card back to normal state and see if the problem persists (I assume you've flashed only the other BIOS). If yes, most likely faulty memory then. Restore the default BIOS and try RMA. If not, try unlocking with a different (XFX or other if you're willing) BIOS if possible.
the memory you have is utter crap, some 290s that had that stuff can max out at around 1300-1400 and thats it and that top end is with good Elpida but most if not all are rubish. my R295x2 has hynix and i can max the bar out 1670 without issues. i would try to avoid anything Elpida Also you have XFX probably one of the lowest brands of 290x cards usually those and powercolor tend to get memory that is rated for exactly the stock speeds. and with no headroom to boot, i have had a few of those before. The thing to watch out for with those types of cards is when the memory fails or has errors at its stock speeds it means you have to reduce lower than stock to get it back to working condition and because there is no headroom in the memory you have to resort to lowering under stock to do it, as you seem to be dealing with that issue now.
