Here is a pic of the heatsink that I'm working with. It's not making much of a difference over the long haul. It slowed the heatup process, but it still ends up near 90c. It's 89c right now and slowly climbing. I think I'll remove the whole thing and make a shim just for the GPU and see if that helps.
Btw, making that heatsink was a royal pain in the arse. I don't think I'll try that again. The shim I can handle. This thing was huge.
UPDATE: So I took this big heatsink off and made a shim out of .025" copper. I sanded it well with 600, 1200, 1500, and 2000, and then polished it a bit. Oblivion was up to 94c with both fans on high for about 40 minutes. I just don't think this heatsink is capable of getting rid of heat any faster. I'll probably take the shim back out and test the temps one more time and see if the temps change.
UPDATE: I took the shim out and ran Oblivian again. Temp still came out at 94 after about 40 minutes. I waited a bit longer and it got up to 95c with fans on high. I've also overclocked too so that might make sense for the slightly higher temps. I'll update my sig with this info.
Even with a 440/1250 overclock, should I still be hitting 94c in Oblivian after about an 40 mins, and 95c after an hour?
UPDATE: Using a plastic bag over my finger didn't work for me at all. I've spend the last two days trying to make things cooler, and I have... for the short term. These changes have just delayed the same final temp. If you wait long enough, the temps rise to what they were before. I've taken the out the GPU memory heatsink and the shim. Everything I do ends up with temps in the same range. I think the main problem is that the GPU fan just doesn't move enough air to remove the heat from the system. If the GPU fan ran like the CPU fan does, I think we'd be a lot better off. So I'm back to stock with just AS5 on my 7800GTX.
I don't think I'll be trying anything else unless it's a way to increase the airflow through the GPU radiator and/or the system case.
UPDATE: I realized that I had a bunch of stuff near the rear of my laptop and the space was cramped where I was doing my temp testing. So I took it to the kitchen table where the temp is 72F and the table is clear. It's been going for over an hour now running Oblivion and it topped out at 91c instead of 95c. I think the stuff behind the laptop was causing the warm air to come back to the laptop and make things hotter. I'll be sure to do my temp testing where I'm not conjesting the airflow.