Geforce 7800 GTX 256, no probs
RADEON1600X pro
all smooth on highest.
I'm running the following...
Athlon 64 3500+
1.2GB of crappy ole PC2700 (which means around 400fsb :()
BFGTech GeForce FX5500 OC 256mb (AGP8x)
My rig runs the Penumbra:Overture demo fairly well (I'd say around the 30fps-ish range at the highest, over 30 on the boat though) with most effects turned up to at least medium (minus bloom, motion blur, and soft-shadowing).
I'm also running it at the second highest available 16:10 widescreen res (dunno what it is, I just got my widescreen about a week ago, so I haven't memorized them yet).
I'm running Palit Geforce 7600GT 256Mb DDR3... together with Athlon 2800 and 1,5Gbytes of RAM... the game runs perfectly smoothly in high-res (I don't remember.. it was 1024x768 or a bit higher), maximum details..
btw. great game.. but I'm afraid of it :) hehe
nVidia GeForce 6600 GT 128mb
(didn't notice any problems with it after I had cleaned it of dust)
G-Force 3 TI 200 pro with 64mb planted on 4 x AGP
Old type Athlon 1Ghz on some crappy ECS mainboard from the last century
256mb of ddr ram working on 333mhz
Full details with all the magic stuff on and 1024/768 screen size. Didn't go below 30 Fps O_o.
No problems playing on this config, apart from occasional :
Sometimes the game slows down, but it dosn't go "slide show" just slow motion.
Nvidia GeForce Go 7300 256MB (with 128MB TurboCache).
I turned everything on except Antialiasing at 1280x800, no problems.
GeForce FX 7600 256MB, runs great!