
MSI took the reference design and upped the ante by increasing the core and memory clock speeds in their NX8800GTS-T2D320E-HD OC offering. The increase in raw speed on the card served as a good reminder that the marketing hype of "more memory = faster" is definitely not always the case as was discovered when put the through the paces against its bigger, but slower, 640MB brother.
As the chart below shows, the NX8800GTS-T2D320E-HD OC is identical to the 640MB version except in the amount of RAM and the core and memory speeds. Both feature nice boosts in speed that lend to impressively increased performance throughout a number of benchmarks and tests.

Apart from a few ultra-high resolution instances, MSI's NX8800GTS-T2D320E-HD OC proved that, with a little extra oomph from end-user overclocking, raw speed still can and does have a major impact on gaming performance; while more memory certainly can't hurt, it isn't the be-all cure to ensure faster performance.
If considering a GeForce 8800 GTS, don't let the lesser amount of RAM fool you: these factory overclocked 320MB GTS cards are packing all the same heat and can perform almost as good and sometimes even better than their bigger-but-slower brother.