Just Cause 2 Poor Performance?

Hello, I bought JC2 for $3.74 from Steam, and I have been getting some really low FPS compared to the benchmarks for my card. They all say I should be getting like 60+ FPS at all times, and I'm getting around 30-40 at all times. It generally doesn't drop below 30, but still.

My monitor is 1600x900. I am playing at the highest settings, just like the benchmarks.

My drivers are updated to CCC 12.8.

PC specs in my signature.

Thanks,