Only way you can get more, if you think the memory is the current bottle neck is to increase the volts to the memory, or increase the timings. Upping the volts could end up with you frying the memory, and upping the timings would slow things down a tad, but this could
be offset by the increased MHz you gain.
Then again, increasing the timings to achieve a higher memory clock could speed things up even though the memory has slacker timings to achieve that speed.
I see you have a command rate of 2T though. You're taking a performance hit right there not having it on 1T. Have you tried it on 1T? Or did you change it to 2T to get the increased MHz?
I'd have a tweak with things.. Run SiSoft Sandra
now - the memory tests - and see what results you get. Then change it to a CR of 1T - it probably wont boot, so lower the mem MHz until it does, then rerun Sandra again, with the best speed you an get using a CR of 1T.
I've found that having a CR of 2 allows me increase the memory speed, but the overall memory performance drops. With a CR of 1T I have to have a lower speed, but I get better results in Sandra on the memory tests.
Not saying this will be the case for you! Every system is different, you just have to try it, change it, bench it and see.