Well, umm... actually it MIGHT be possible. Check around your BIOS if you have a RAM multiplier... it should normally allow async operation of PC1066 on a 400MHz FSB. If you can keep that multiplier but have the FSB at 533MHz then your RAM should go very, very fast.
That's the only option I see though... DRDRAM clock gens so far don't support fully asynchronous operation.
We'll have to wait and see what SiS does with them...
Yes, I have my multiplier set at 4x, at a 533/133 fsb. But alas, I only got a 200 point increase in 3dmark, but all games run flawlessly. That is the important thing.