I have read that at some point it's kinda like connecting your garden hose to a fire hydrant and expecting more water to come out.I'll be here .
If you would of had any conflicts with the new ram , you would have got a lot of BSOD'S [Black Screen Of Death]. at boot , and never booted into windows.
You could have two sticks of even faster ram , but there are so many variables [ cpu, motherboard. etc.]. you still might not be any faster .
Hope this explains it a little better for you .
Nick