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.





The performance improvements afforded by the BFG's increased clock speeds isn't an awful lot. Despite Clear Sky being GPU limited and - at 1,920 x 1,200 at least - seeing almost linear performance scaling, the frame rates are above 30 frames per second so you may not notice the performance differences between the three GeForce GTX 285s. Moreover, the Sapphire ATI Radeon HD 4850 X2 scales really well in Clear Sky and it's almost 30 percent faster than BFG's heavily overclocked 285.