AMD Phenom II X6 1075T, X4 970, X2 560, Athlon II X4 645, X3 450 & X2 265 CPU's
 

For the X4 970 I was at 4.133GHz (206x20) and for the X2 560 I was at 4.154GHz (208x20). When it came to the X6 1075T the multi was locked so I had to rely on the reference clock. With a multi of 15x I knew I was limited but I dove in with an open mind. I raised the reference clock 15MHz at a time until I was no longer stable as before. To my surprise I was able to push the clock to 275MHz and boot but it was not stable enough to pass any tests. I slowly backed down the clock 1MHz at a time until I was Prime95 stable and to my amazement, that was at 270MHz on the reference clock! I did have to drop the HT and memory dividers to compensate but my final overclocked speed was 4.052GHz (270x15), which was a whopping 33% total overclock!

http://www.overclockersclub.com/revi...n_645_450_265/