Slow speeds on Samsung 840 Pro 256 perhaps due to controller?

[Spiritman]

I recently installed a Samsung 840 Pro 256 GB SSD in my computer, and have been disappointed by both the write and read speeds which well below the norm. I've done a lot of online reading about this topic, and a number of posts suggest that the slow speeds are related to the Marvell controller that is used on my Gigabyte motherboard (see the description of my system below). I am confused by the references to a Marvell controller versus an Intel controller (which is supposedly much better than the Marvell), as I'm not sure which type is on my Mobo. My SSD and HD are connected to the SATA III 6Gbs ports on the Mobo. Is there anything I can do to address the apparent problem with the controller and thereby improve the slow SSD read/write speeds?

My system:
Mobo: Gigabyte GA-P55a-UD3, v. 2 (socket 1156)
CPU: Intel i7-870 @ 3.5 Ghz
GPU: Gigabyte GTX 660 Ti OC
SSD: Samsung 840 Pro 256 Gb
HD: Western Digital Caviar Black 7200 rpm

Thanks for any and all comments and advice.

Spiritman
Seattle, WA, USA

[Rob85]

try disable power saving feature "c6 state" in bios. that throttles SSD performance on my z68 board

but i believe your mobo only has the marvel sata3 ports so you wont get the best performance.... the Intel controller first featured with i7/5 2nd gen motherboards i think