I have M17X R4 /w 3630QM, 980M. GPU installation is nicely done and I have a job for CPU. At the first time I thought about 3940XM OEM, but it's beyond my budget. Too Expensive.... almost over 600 USD! So I'm trying to buy 3940XM QS instead, but 3920XM OEM is on my mind either. 3940XM QS is manufactured later than 3920XM OEM, and if that is true 3940XM QS could be better than 3920XM, even 'OEM'. (I'm told that!) So I'm still hesitant to buy CPU. Is there anyone knows which one is better for overclocking stability? (most important thing is temp, or 'yield' another word?)