Does Using Onboard Graphics Limit Overclocking?

[Tazul]

Hi I just upgraded my motherboard from a Gigabyte GA-MA-770-DS3 to a Foxconn Destroyer 780a. Now I had to RMA my 8800GT and its taking forever to come back and i want to start overclocking and i am using onboard graphics. with my Gigabyte motherboard i was able to reach 3055MHz at 1.45v with my Athlon 64X2 5000+ brisbane (not Black Edition) but for some reason i cant get 2900MHz stable with my new motherboard which is suppose to be able to overclock very well. Could it be because im using onboard graphics? Does that limit my overclocking? I just want to get at least 3GHz again. Thanks in advance.