Whoa wait a minute, your CPU idles 60Â°c. If that is the case then the CPU is more then likely throttling under load.
D/L Throttlewatch from the link I provided makryu and run Orthos or Prime and see if your CPU is throttling. Throttles around 70Â°c.
My 7800GS can idle at 35Â°c if I want, cold bug though so I don't let it. Idles now at 38-41c.
If your card is idling at 47-49c that tells me you need better system cooling.
The 7800GS dumps all the hot air into the chassis..freakin oven in there.
Do like I suggested to makryu and pull off the side panel and point a house fan into it and see how your system performs.
The cpu idles at 58C with the case open, when I stress it, it goes to 61-63.
I have the 1300xt in there right now, and the gpu for that card is 46-48 as well, so its the same as the 7800gs.