After taking a little additional time with the latest beta Catalyst drivers and the Thief patch, we tested them on an Intel based system running on a 3570K CPU. The system was tested at base speeds and during an easy overclock. Previous testing with Mantle showed a good boost to performance when the system was overclocked and we expected to see that here as well.
When we tested the patch and drivers on an AMD based APU we received a performance boost from 5.65% up to 21.26%. On a similar configuration, running on an Intel CPU the range was 4.2% to 24.87% performance increase with Mantle enabled. While the graphics were set to Very High, the 4.2% performance increase was small, but any boost in performance is nice when it doesn’t cost anything.
Once the Intel system was overclocked, the scores changed a little, on Normal settings, the Average FPS went from 73.3 to 79.8, an 8.86% boost due to overclocking. While not a huge amount does show overclocking does affect Mantle’s performance. A more aggressive overclock should result in a better boost.
While we can see that Mantle can affect performance, what does concern me is that the DirectX API seems to be limited to a maximum framerate of the low 60’s. On the surface that’s not bad, however when consider the average FPS, that limitation could be affecting the FPS. Perhaps those scenes could’ve gone a little higher and adjusted the score changing the overall difference between DirectX and Mantle. Then again, maybe that maximum was just a few seconds and wouldn’t make a big difference in the average.
Legit Bottom Line: Nobody would turn down a double digit performance increase, especially when it comes from a free driver update and a game patch. Thief shows that Mantle does affect performance by up to 24.87%, even doing a simple overclock can boost the performance a bit further. We will be keeping a close eye on how Mantle plays out, and hopefully more games will implement it.