According to TheInquirer the upcoming Nvidia NV30 will probaly run at around 400Mhz :
SOURCES IN THE KNOW tell us that 400MHz is what Nvidia is aiming for their NV30 card. I need to clarify things and say we did once hear from a Senior Nvidia executive that, "there is no such thing as this frequency. It's all in the yield," suggesting that chip frequency is being determined after companies have pre-production samples often called A11 silicon.
So what Nvidia expects from NV30 is that it'll run at around 400MHz or even higher depending on the yield of chip. We also confirmed that card will have 8 pipelines. Of course, as many reported before, the Nvidia chip will sport 120 million transistors built on 0.13 microns.