Hello All:
I have a QX6700 and I bought a GTX and used the larger O-Ring to bow it. My temps went up 5 degrees. So I pulled the chip and with a straight edge determined that it had a high spot right in the middle. So I got some 1000 grit wet or dry paper and in 15 min. it was flat and so I bought a fusion and put that on and it works fine now (below 60 degrees C. full load). So it depends on your CPU.
Ed