Robin, don't sell your 5970 card, it's a really good card, what we need is good crossfire profile from ATI, or good crossfire suppord from devs.
There is only 1 card from ATI what is faster than yours, it's 6990 and it's crossfire card too, so same problems with CoD, if you buy one GPU card you downgrade your computer.
all 5970 is downclocked from factory, so i overclocked mine and get about 25% faster 5970 than default, of course i cannot say overclock it, that is risky but i put link to you, i do it and my card is very fast at moment and stable with factoryfan.
i raised my voltage only 1 notch as you see at the link, only software i use was MSI Afterburner, and i overclock only when there is need to it (A-10 and CoD)
http://www.guru3d.com/article/overcl...on-5970-guide/
Kankkis