Windows 7: Does GPU overclocking level depend on the motherboard?

I had just noticed something very nice, and attractive, ever since I upgraded my motherboard, my other hardware components have been performing much better.



Specially my GPU. I own a sapphire HD770 Vapor X OC That comes overclocked at 1100 and 1300 Clock and Memory respectively.

Well in my old motherboard I was barely able to take it over 1120 and 1320 respectively. At the moment I was able to raise the settings over to 1340 and 1330, but I haven't wanted to go higher and I am not encountering any loss of FPS in any game I've thrown at it so far. But it already beat the old overclocking attempts with my old motherboard.

So, how much does OC has to do with the chips themselves in comparison to the motherboard?