S.T.A.L.K.E.R. requirements

I admit I have been surprised when I recently read the official recommended requirements from THQ for their upcoming FPS game, S.T.A.L.K.E.R., Shadow of Chernobyl:

Minimum Requirements

None given, but compatible with DirectX 8 (as well as DirectX 9).

Recommended Requirements

CPU: AMD Athlon 64×2 4800+ or Intel Core 2 Duo
Graphics: 3D Hardware Accelerator Card Required – 100% DirectXR 9.0c compatible 256MB (Geforce 7800, for example)

This is a much higher level than expected for such a game. It means that most of us would have to upgrade to a top-notch PC hardware to play well. They indicate that it should scale down well (because of the lengthy game development, they say!). But I don’t know. THQ does not even gives a minimum requirement. Let’s assume that it will work well on a single-core CPU (it should be the case).