Guys, this 21x multi is possible on the P6T Deluxe without turbo as well, using the 1303 BIOS. I can personally confirm this. Just look at the P6T Deluxe discussion thread for more info.

It does have a bug that I hope is resolved though, and I would reckon it is on the R2EG as well. Under extremely heavy load, such as Linpack using LinX, the multi will drop back to 20x. Since the 20x is way more unstable than 21, a perfectly stable OC now becomes unstable due to the 20x multi under heavy load.

I believe this is a bug with the TDP limitation, I really hope Asus can correct it. Prime95 was not enough to make it go to 20x for me.