New
#11
Where to start. Just one of those cards should be plenty enough to play any game at just about any resolution at max settings plus some AA. The odds are good that something else in your system is holding you back. Drivers can also be a problem with those particular cards.
If it's an Alienware product you might try asking them why your system isn't performing up to your expectations. You might also try running 3Dmark Vantage because it will give you a good starting point to gage your system against systems like your own.
As for your processor speed changing. The i7 uses a turbo mode which changes the CPU multi depending on load and there is also a version of speed step and or C1E halt state which down clocks the CPU when it's idle but neither of those should be causing you any problems with your cards.