Have you run other games to see if its just an issue with this game or all games?
Have you run any benchmarks on this yet which might point out a bottleneck in performance, where hardware such as RAM might not be scoring as well as it should etc?
I also saw that your motherboard may have a newer BIOS flash available for it. If you want to go this route with a BIOS flash, just be careful and make sure power is not disrupted in between the flash process.
In the past when I had problems like this it was either Video Card, RAM, or Main Board Hardware or BIOS overclock Config issue.