Help with improving memory speed (AMD)

[HankScorpio]

Hello, I'd like some help improving my memory speed if possible.

I ran my amd overdrive benchmark and my memory speed is really low compared to other results

Integer Compulation - 18880

Floating point compulation - 18860

Memory speed - 3272

Cache speed - 17131

Sys performance - 5814

My cpu is AMD phenom x4 955 be OC'd to 3.6ghz

My memory is ddr3 Corsiar x2 2gb 1600hmz and patriot ddr3 x2 2gb 2250mhz

mobo is gigabyte GA-890FXA-UD5

I went into the bios M.I.T section and put the 'memory clock' setting from 4 to 8(max) and says 1600mhz.

Is this all I can do, or is it even increasing the ram clock speeds? in my mobo manual it says *Support for DDR3 2000(OC)/1333/1066 MHz memory modules*

As you can probably see I'm a newbie when it comes to this stuff, just wondering.

Corsiar in slots 1+2
http://i210.photobucket.com/albums/bb110/ReisD/corsiar.png

Patriot in slots 3+4
http://i210.photobucket.com/albums/bb110/ReisD/patriot.png

Thank you very much for any help.