As this issue seems to have been resolved with new drivers I'll mark this thread as solved now.
@goughy000 wrote:I risked it and bought an XFX R9 280X and... No leaks so far! Played longer since getting this card than when I had the 5870.
It's not the right solution because someone needs to fix this for the 5xxx and 6xxx GPUs.
I'm tempted to say this is an AMD driver issue but its difficult to tell. I also wouldn't be surprised if this magically fixes itself when the mantle update gets released which is probably why it's not getting any attention.
That series of card isnt affected so you wont see the leak.
Sorry to bring bad news but I have a r9 280x with latest driver (13.12...and tried them all) and still have this memory leak thingy.
What? Than you are the first one, arnt you?
