Pls advise on H55M-USB3 graphics problem

Ok, so I have the
GA-H55M-USB3 paired with an i3 540.
2x 2GB Corsair XMS3 (Unlocked)
Nvidia GTX 260
Gview Titanium PSU 500W

My FPS in WoW is really poor. I was using the same GPU in my old setup (ga-965p-ds3, C2D E8400) and never had any graphics issues. With the new setup I have 70-90 fps when I first login, then it drops quickly to 30-50 in open zones or 15-25 in Stormwind. When turning or flying around major cities it gets very jittery and stutters a lot. Using the same vid card with the old setup I used to get 120+fps in instances and never had problems in major cities.

This problem occurs when everything is set to Optimal Defaults in BIOS and overclocking in any which way only seems to make the problem worse. Does anyone have any suggestions as to what the problem might be?

BTW I've tried the latest vid drivers (260.99) and earlier versions with the same results, updated to latest BIOS (F11) and updated DirectX.

Any help is appreciated.

people may call noob on me, but...
A: isn't H55 motherboards have an on-board graphics chip?
B: is THAT graphics enabled as your primary?
C: ... sorry that's all I got.
if thats what the problem is, then all good, easy fix i'm sure.
If not, again sorry.

EDIT:
Even your CPU has something to do with graphics in it (not 100% sure how it works, if anyone else can shed light on this that'd be great.

Ba!nesy said:

people may call noob on me, but...
A: isn't H55 motherboards have an on-board graphics chip?
B: is THAT graphics enabled as your primary?
C: ... sorry that's all I got.
if thats what the problem is, then all good, easy fix i'm sure.
If not, again sorry.

Click to expand...

It does indeed but it also has a x16 PCIE slot which my card is in and running. If only the solution were that simple Thanks for that though.