I finally decided to try out one of those Nvidia 8800GTs that have gotten the spotlight over the last few months. So here's a bit of comparative numbers.
2.4 GHz Core2 Duo
2GB RAM
Nvidia 7900GS 256MB
Aquamark reports:
GFX 19,218
CPU 14,012
Overall 114,008
After major brain surgery to rerun all of the power cables in the box, since the 8800 is an inch or two longer than the 7900 -- the cabling in this box is way too tight, Aquamark reports:
2.4 GHz Core2 Duo
2GB RAM
Nvidia 8800GT 512MB
GFX 26,835
CPU 14,146
Overall 137,703
...hmm, almost exact match for Eliaures's GTX...
By that score, you'd think the 8800GT is only 25% faster than the 7900GS. I did a couple quick tests with DX2 and Oblivion (yes, I reinstalled just for this), and I'm seeing at least 50% higher FPS in DX2, and I can smoothly run Oblivion at the default "High" setting without any tweaks.
More meaningfully, I ran some tests with my own home-brew game engine. There I see FPS almost double across the board. Nothing like exploring a dungeon at 1,500 FPS... at least until the physics breaks (note to self: "Fix the time step").
For some extra comparison, I put the 7900 back my previous dev system:
3.6 GHz P4
2GB RAM
Nvidia 7900GS
GFX 12,165
CPU 10,092
Overall 75,892
I didn't expect the GPU performance to drop that much. For all of the CPU intensive tests I've done between the two systems (mostly with ray tracing), the Core2 comes out only 10% faster than the P4.
I had also planned to run Aquamark on the first-gen 6800GT spaceheater that I was using in the older system. But I forgot, and was too cranky after screwing around with cases by that point to swap things back again. The older system is a 3-year-old high-end Dell gaming system XPS something or other. It also has the flimsiest construction I've ever seen, and plastic pieces literally fall off when touching it. Working in that case is like trying to play Jenga while a herd of kittens attack the pieces -- you need ten hands to hold everything in place. And then something you weren't even looking at falls off, and you have no clue where it came from. That case made me swear to never buy Dell again.
PS: Nvidia, I hate your product naming/numbering scheme.