Instantaneous Performance and Image Quality
StarCraft II: Wings of Liberty so far turns out to be quite modest in terms of computer hardware appetites (without forced antialiasing). At the highest graphics quality settings you can achieve a playable frame rate with almost all contemporary graphics cards available on the market.
We decided to try the game at different graphics quality settings on similar graphics cards to check how scalable the engine is. Besides, we also wanted to check out the influence different central processing units have onto actual gaming comfort. We took two popular graphics cards for this test: an ATI Radeon HD 5850 and an Nvidia GeForce GTX 460 1GB. Both cards were tested together with Intel Core i7-975 Extreme Edition and Intel Core i7-920 processors.
For each of the four quality profiles we were recording the instantaneous performance with the Fraps 3.1.3 utility for 60 seconds. As usual, we tried to make the test scenario as variegated as possible. Anyway, we captured a few screenshots that can help us evaluate the difference in image quality between the game’s settings profiles.
Here are the results:
The game does respond to more CPU computing power. On average, extra performance provided by the Core i7-975 EE gives an 8% increase in frame rate. Even more significantly, minimum frame rate rises accordingly, which is going to help if two armies collide.
There is little difference between Radeon HD 5850 and GeForce 460 in Ultra mode. Both participants react similarly to dissimilar workloads presented in the game.
The Ultra mode provides the best possible picture quality, but what can you do if you need that extra bit of frame rate? Well, High mode is a real alternative in StarCraft: Wings of Liberty. A drastic improvement in frame rate with a small quality compromise is an acceptable bargain, when average fps skyrockets to a hundred. You are going to miss out on some fine detailed textures, HDR lighting and reflections, as well as several other special effects, but in reality you are still going to play the StarCraft II.
The difference between Intel Core i7-920 and Intel Core i7-975 XE is only 7 fps, so, it proves that CPU power is less important that GPU performance for the game.
Say goodbye to physics and more or less advanced lighting model in Medium mode. Water surface, shadow models and post-processing also suffer significantly from this quality option. In terms of performance, however, Medium mode raises the bar to an impressive level of 120 fps. You will be hard pressed to find any place in the game where Medium settings might seem to be hard to handle. With a different CPU the GeForce GTX 460 manages to establish itself as a winner at 128 fps, while the Radeon HD 5850 trails behind at "only" 120 fps.
Finally, the Low mode is the lowest-quality one in StarCraft II. The frame rate of the game does grow up significantly, but given the quality sacrifice you will have to bear, it is hard to imagine any one actually going to use this mode. It is miles behind Medium and you probably would rather play the original StarCraft game instead.
The CPU’s influence is roughly the same as seen in previous cases and 200 fps mark can be enjoyed at all times.
Summing it up, we can note that different quality settings affect the game a lot both in terms of quality and speed. If your system is incapable of providing adequate level of performance, try switching from Ultra to High. You will not be giving away that much in terms of quality, but your frame rate will benefit significantly.
In terms of CPU choice, it makes more sense to prefer the higher clock-speed to extra cores. Due to DirectX 9 and Blizzard's intention to make it work on the maximum possible amount of systems, the game is generally badly optimized for multi-threading and struggles to load up more than two cores despite of Havok physics engine.
In terms of GPU architectures there is virtually no difference with both ATI Radeon HD 5850 and Nvidia GeForce GTX 460 1GB showing similar patterns of behavior, as predicted.