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.






S.T.A.L.K.E.R. is the game engine equivalent of a greedy friend - the guy who'll spend the whole party stood next to the buffet, and even then be rifling through your fridge to hunt out yet more food to eat. If there's something to be had, S.T.A.L.K.E.R. will have it.

It's therefore no surprise to see the Vapor-X have a little bit extra speed in S.T.A.L.K.E.R. over the 1GB HD 4870. At 1,280 x 1,024 there's not too much difference between the two cards, but the middle resolutions of 1,680 x 1,050 and 1,920 x 1,200 show a big win for the Vapor-X over the 1GB HD 4870. For example, at the latter resolution the Vapor-X can churn out a smooth minimum of 25fps while the 1GB HD 4870 stutters to a minimum of 16fps. The performance lead over the 1GB HD 4870 tails off at 2,560 x 1,600, as the limitations of fundamental hardware (shader processing speed, memory bandwidth etc.) level the playing field.

It's only at 1,920 x 1,200 and 2,560 x 1,600 that the Vapor-X keeps up with the GeForce GTX 275; at the lower resolutions, the GTX 275 is a good bit faster. For example, while the Vapor-X can run the game at a minimum of 25fps at 1,920 x 1,200 to the 23fps minimum of the GTX 275, the GTX 275 manages a 27fps minimum and 35.5fps average at 1,680 x 1,050 to the 23fps minimum and 31.6fps average of the Vapor-X.