After half hour of gameplay , I touch my 6990 and it was very hot like I'm cooking something , is that normal .?
it going to get hot in game play. the gpu fan and drivers should have speed the fan up to where you can here it. if not download asus afterburner or a program like it and make a fan profile that turns the gpu fans on max at 50-60c.
GPU's can very easily reach temperatures in excess of 75c, you could very easily burn yourself or cause a short. the GPU is an electronic device I can't stress enough that touching it at any time while the PC is on is a very silly idea.
I also have another pc ( old ) with 8800gt nvidia from 2008 and I use HWmonitor , and it record one of my game (in normal setting ) 94 c in 10 minute . And I was playing games with this old pc from 2008 and no issues
Your GPU is bound to get hot during game play. It also depends on the type of game you are playing. Not to mention if you're running other applications at the same time. If it uses most your computers resources then expect it to be really hot.
This is the reason why hardcore gamers have cooling systems built.
There are a lot of PC temperature monitors. You can take Real Temp for example. This really comes in handy. This way, you don't need to touch your GPU and risk being injured to be able to tell how hot your computer is.
94C seems really too hot for a 8800GT. Since it's an older PC, you probably have an old case with poor ventilation. Make sure you have many case fans, at least one in front and one behind to create proper air flow. Or it could simply be the 8800GT fan that got clogged with dust if you never cleaned it since 2008.
Did you check the temps with hwmonitor for your 6990? Since it's a dual-gpu card it's normal that it gets really hot. I guess 80-85C are normal temps under heavy use like during game play.