I am running a sandisk sata 3 120gb ssd on an older socket 775 board with a PCIe sata 3 controller.
Your benchmarks are 3x mine. I don't think your going to get it much faster with out the use of rocket fuel.
I just did a upgrade that's how these score happened i use to also have a 775 motherboard the old Asus maximis formula and i wanted to install my 2 ssd's on it. Some as i installed them & went to boot up..Nothing tried everything it wouldn't work so i but everything back to the way it was still nothing.So i had a pro from japan look at it a computer genius and he was clueless some how the board got corrupted he also said that particular board was the worst board asus ever made for returnes