Best place for the facts is the Steam site... CS:Source is essentially just 1.6 ported to the 'Source' engine (you'll notice Half Life 1 'Source' is also available - which could be interesting ) As it stands, I don't think it's anything like as playable as 1.6 (IMO) but give it time...) It's true, therefore, that while you might be happily running 1.6 at 100fps with your GeForce4, don't expect the same performance from Source, as it puts far more pressure on CPU and video card! This is a separate thing from the proposed 'Counter-Strike 2' which I believe will be a complete remake and release sometime in 2005...according to rumours...