Poor performance of ExtremePro 240GB

The reason I’m using a PCIe adapter for SATA is that it’s 6Gb/s while the build in SATA on the motherboard is only 3Gb/s. I will try the SSD on the motherboard SATA headers to see if it makes a difference, but I can’t see it being any faster.

The relevant specs for this computer are:

ASUS P5B deluxe

Processor: Intel QX6700 (quad core 2.6GHz)
6Gb 800MHz SDRAM

PCIe card: Highpoint Rocket 620A plugged into a PCIe-x4 port, though it’s only a x1 card.

I have not installed any specific drivers for this drive or the controller. It just works. I am using an Ext4 filesystem on the SSD, though that shouldn’t be relevant to the speed test as that’s done on the drive itself, not the partition.

What else do you need to know?