S.T.A.L.K.E.R.: Clear Sky

Publisher: Deep Silver

S.T.A.L.K.E.R.: Clear Sky is the prequel to GSC Game World's sleeper hit S.T.A.L.K.E.R.: Shadow of Chernobyl and was unfortunately released in a bizarrely unfinished state and it's taken some time for the game to reach the levels of stability that we expect from a game. However, with the new 1.5.07 patch, Clear Sky runs great and as you would expect it to.

Clear Sky uses a heavily tweaked version of the X-Ray engine, which debuted with Shadow of Chernobyl and was updated to support several new graphical effects using DirectX 10 (and later DirectX 10.1 through the 1.5.06 patch). The improvements include enhanced visual effects like 'God Rays', wet surfaces, volumetric light and smoke, depth of field blurring, and screen space ambient occlusion lighting as well as better textures.

We used a custom timedemo for our testing, which incorporates many of the advanced effects introduced with DirectX 10 – we also enabled DirectX 10.1 on the Radeons. However, due to the intensity of engine, we have set the in game details to "High" instead of "Maximum" and have left anti-aliasing disabled for the time being.






As the Asus Radeon HD 4890 is a stock clocked card out of the box, it performs identically to any other reference HD 4890. There's no clear performance winner in S.T.A.L.K.E.R, with the HD 4890 and GTX 275 trading blows at their default clock speeds, although the HD 4890 does start to edge at the ultra high resolutions of 1,920 x 1,200 and 2,560 x 1,600.