No problems with turbo here, x21 is working just fine after BIOS 07/24

Moving up to @4.3GHZ(205x21) 1.26v
12GB RAM, 6GB OCZ 1333MHZ CL7 + 6GB Corsair 1600MHz CL7, running @1266MHZ 6-7-6-22 1.65v
VVT=1.21v, NB Core=1.12v (both BIOS set)
Still going strong with x18 Uncore

w3520 @4.3GHZ(205x21) 1.26v, 12GB 1266MHZ 6-7-6-22 1.65v, HyperPi32M Stable



The read-bandwidth has dropped by about 3k to 17k-read and 44ns latency (vs 20k-read and 41ns of 6GB Corsair) but I'm still having a hard to track the effect of "slow RAM" on my real-life applications. I guess both of them are overkill anyways.
Just started experimenting with and 12GB, and I may go back to 6GB. Just made a 2.5GB RAMdisk and I have to see is I can put it in good use.
Even tho I haven't tested the total stability of @4.3GHZ for 24/7 yet, but it is running so smooth that I may get used to it .