Gaming PC lag after a few minutes of play

[Nasakenai 34]

My game generally runs fine with everything maxed, however sometimes it just randomly starts lagging horribly - like under 10 fps basically unplayable. I don't know why it happens, sometimes alt+tabbing out and back in fixes it or disconnecting and reloading fixes it (until it happens again).

Here are my specs:

Alienware m18x 3.4 i7

16gb ram

2x 2gb 6990 in crossfire setup

I don't see any reason why it should be laggin, I can run Crysis 2 and Bf3 on ultra with 60+fps. I've also had a similar issue on my second machine (desktop) as well.

Anybody else seen this? Anybody have an idea what it could be?

[Alopex 46]

I have also experienced this issue with my PC. I think that it may have something to do with having a CrossfireX setup as I have two HD4870s in CFX with identical symptoms.

As even a single HD6990 is overkill for ARMA 2:OA, you may want to try disabling CFX under Catalyst Control Centre, then launching the game (running on a single card). I haven't tried this myself, as I play on a gaming laptop most of the time, but it seems like it may be worth trying.

I hope that helps.