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.





Following a couple of disappointing experiences in Crysis and Call of Duty: World at War, the Sapphire Radeon HD 4850 X2 is back singing a much more positive song in S.T.A.L.K.E.R.: Clear Sky. There's a frankly massive gulf in performance between the 4850 X2 and Nvidia's GeForce GTX 285 - at 1,680 x 1,050 0xAA 16xAF, the gap is almost 27 percent and it increases to 39 percent at 1,920 x 1,200. At 2,560 x 1,600, neither delivers a playable frame rate so the performance difference is essentially negligible unless you start lowering quality settings and, for the sake of completeness, the gap is a healthy 34 percent in favour of the 4850 X2 at this setting.