Here is the standard set of specs used in what appears to be the "standard" dev machine, according to the German magazine GameStar:
* AMD AthlonXP 2500+ or 2600+ (Barton Core, 333MHz FSB)
* 1024MB (1GB) RAM
* ATi Radeon 9800pro, AGP with 256MB video RAM
The above settings would likely run the game at a fairly decent clip, and more importantly, if such machines are in use for development, they obviously run the games with all the settings "turned on."
Note that there are MANY different types of PC in use at the BethSoft HQ. From what I understand, the PC used to render that mind-blowing trailer used a pair of GeForce 6800 (GT or ultra) cards in SLi-mode. Also, the machines have varied processors; a dev (Steve Meister, a.k.a. MSFD) noted that Dell is the company's main supplier of PCs; he apparently works at debugging and optimizing from his computer, which is the same as the one mentioned by GameStar, except that it has a 3.0GHz Pentium 4.
Additionally, here are my own specs. I know I can't really brag about these online, but they are fairly acceptable nonetheless, and pretty good for a college student's budget:
* AMD Athlon64 2800+
* 1024MB (1GB) PC3200 400MHz DDR RAM
* ATi Radeon X800XT, AGP with 256MB video RAM
I would suspect that my machine will run Oblivion excellently.
Ovo je sa njihovog foruma