Date:
Tuesday , May 19, 2009
Author:
Brent Justice
Editor:
Kyle Bennett
Google +1

Real World Gameplay CPU Scaling

Four processors; Intel Core i7 920, Intel Core 2 QX9650, AMD Phenom II X4 810, & AMD Phenom II X3 720 BE. Seven games. REAL WORLD GAMEPLAY at stock clocks and all overclocked to 3.6GHz, head to head, & apples to apples.

continued...

Gameplay Summary

Burnout Paradise

Burnout Paradise played very well on each system. The Radeon HD 4870 X2 CrossFireX configuration was able to push the game to 2560x1600 with 8X AA enabled and the highest in-game settings. Due to an FPS cap the game remained at this 60 FPS level for each CPU. None of the CPUs here allowed us to raise our playable settings beyond 8X AA at 2560x1600 at either default or overclocked frequencies. What we did find though is that some CPUs provided more consistent framerates in comparison. Notably, the two Intel CPUs, QX9650 and Core i7 920 allowed the smoothest framerates. The AMD Phenom II X3 720 BE had the most dips in framerate, though the game was still playable at the same levels as the other CPUs.

In this game, no CPU provided a real noticeable advantage in-game, and the experience for all intents and purposes, equal.

Crysis: Warhead

Crysis: Warhead, unlike Burnout Paradise did have some rather large performance differences between each CPU. We were using the same graphics setup (Radeon HD 4870 X2 CrossFireX) for each CPU, so the only difference is the CPU. We were certainly able to get more out of the Radeon HD 4870 X2 CrossFireX configuration with the Intel CPUs at default and overclocked frequencies than we were with the AMD CPUs.

With both AMD CPUs at default frequencies we were not able to use AA at 1920x1200. With the Intel CPUs at default frequencies we were able to enable 4X AA, providing a very noticeable visual quality improvement. When we overclocked all CPUs we were able to take the Intel CPUs up to "Enthusiast" spec for the highest in-game settings possible, yet the two AMD CPUs were still playable at "Gamer" but with AA at 4X. It took an overclock to 3.6GHz for the AMD CPUs to match the performance of the Intel CPUs at default frequency in this game.

This game is sensitive to clock frequency, and apparently heavily favors the Core 2 QX9650 and Core i7 920 for the best performance.

Fallout 3

Fallout 3 performed very well and we were able to play at 2560x1600 with 8X MSAA enabled across all CPUs. Like Burnout Paradise we were not able to increase the graphics settings any further, even with overclocked CPUs. Like Burnout Paradise we found that overall both Intel CPUs did give us smoother, more consistent framerates.

This game also seemed to be sensitive to clock frequencies, but that did not result in us being able to play with higher in-game settings which are GPU bound.

FarCry 2

FarCry 2 performed very well at 2560x1600 with 2X AA. This was lower than what we would have thought playable with a Radeon HD 4870 X2 CrossFireX configuration, but we think this is related to GPU limitations, and not CPU. None of the CPUs allowed us to increase the graphics settings any further. Like Crysis: Warhead there were some very noticeable performance differences between the Intel and AMD CPUs.

Our results clearly show both the QX9650 and Core i7 920 at default frequencies provided noticeable performance improvements. The same results were duplicated when overclocked as well.

Overall, no CPU allowed us to improve the visual experience, but in terms of performance the two Intel CPUs clearly lead in performance in this game.

Flight Simulator X

Flight Simulator X was very CPU dependent, and we found it was the "Traffic" settings which impacted performance the most between all CPUs. We were able to set other settings like Scenery, Weather and Aircraft, resolution and AA/AF settings at the same levels. The AMD CPUs were the slowest, simply put, the gameplay experience wasn’t that immersive with all the traffic basically turned off at the "Minimal" setting. This was necessary though, and even at this setting the performance was still slower than the Intel CPUs.

At default frequencies there was even a difference between the QX9650 and i7 920, with the QX9650 pulling in a better gameplay experience. The QX9650 is clocked at 3GHz, versus 2.66GHz on the i7 920, and this clock advantage seems to pay off in FSX. When overclocked we finally see the two AMD CPUs manage to make it up to the same performance as the QX9650 at its default frequency.

This game proved to be extremely sensitive to clock speed and clearly favored the two Intel CPUs.

Grand Theft Auto IV

Grand Theft Auto IV, like FSX also seemed to be sensitive to CPU performance, but in a different way. Unlike every other game we tested this game didn’t seem to be affected too much by CPU frequency (at least on the Intel CPUs) but more so between the differences in the AMD Phenom II X4 810 and Phenom II X3 720 BE.

At default frequencies the Phenom II X4 810 was slightly behind the two Intel CPUs, but the Phenom II X3 720 BE dropped way behind. When we overclocked each CPU the Phenom II X4 810 at 3.6GHz matched the gameplay experience of the Core i7 920 and Core 2 QX9650! However, even though the Phenom II X3 720 BE was also at 3.6GHz its performance still fell well behind. The major difference between the X4 and X3 is the fact the X4 (and i7 and QX9650) are all quad-core CPUs, while the X3 is a triple-core CPU. Since we found this game not to be a sensitive to CPU frequencies, this is the only game tested here which is sensitive to the width of multithreading beyond 3 cores.

Overall, the Phenom II X4 810 can match the performance of the Core i7 920 and Core 2 Quad QX9650 in this game, if you overclock it. Otherwise, at default frequencies, the two Intel CPUs do take the lead.

Left 4 Dead

Left 4 Dead performed EXTREMELLY well as we had anticipated. The Radeon HD 4870 X2 is certainly not holding this game back. We were able to play at 2560x1600 with 12X CFAA and Quality Adaptive AA enabled. None of the CPUs allowed us to increase this setting. This game plays so well that even with the slowest CPU here the gameplay experience was at the highest levels, and the gameplay was smooth.