I have a Late 2011 17" MBP (MacBook 8.3) with the BTO 2.5 GHz Core i7 (Sandy Bridge, I7-2860QM). Currently I have on it 8GB ram through two 4GB Kingston HyperX 1600Mhz (the green ones) which have worked without a hitch for almost 3 years now. Seeing that Apple doesn't seem to care for making 17 inch MBPs anymore i will hold onto this one until it dies, as anything smaller, even if its retina, feels cramped to me. So, I'm pondering on upgrading the ram to 16GB... normally would just get the exact model of Kingston memory to assure compatibility, but Kingston Green HyperX is discontinued. They have replaced then with the Black Hyper X, which should work as well. So, I am torn between the Kingston Hyper X Impact Black 1600 CL9: http://www.amazon.com/Kingston-Hype...d=1428289696&sr=8-2&keywords=HX318LS10IBK2/16 Or their 1866 CL10: http://www.amazon.com/Kingston-Hype...d=1428289696&sr=8-1&keywords=HX318LS10IBK2/16 I know very well that the difference in CL/MHZ speed will be unnoticeable at best in anything but benchmark tests and bla bla bla. I am not asking about which one is faster, what I am asking is if anyone knows if the 1866 CL10 will work on my particular model of MBP. Why you say? Why not just get the 1600 Mhz then if there is almost no difference? The answer is very simple: because where I live (Japan) the 1866 one can be found at 20 dollars CHEAPER than the 1600!!! yes I know it sounds retarded but that's how it is. So, I'm thinking that just because of that I should get the 1866 for future proofing. Likely my next purchase will be a PC (I only buy 17 inch laptops) so I might as well buy something that might work in my future machine. I also do a lot of Final Cut X video editing and RAW processing on Lightroom, as well as some Bootcamp gaming, so maybe I would also get a very infinetely small performance gain with he 1866/CL10 over the 1600/CL9, just maybe. The reason why I'm torn is becuase I know FOR SURE that the 1600/CL9 will work because that's the current speed of the modules I have now, also one of the reviewers at amazon has also a late 2011 MBP and the confirms it worked for him. I dunno however if the 1866/CL10 will work. THEORETICALLY SPEAKING, the intel chipset on my MBP does support those speeds. Nevertheless, asking Kingston does not help cuz they just sent me to buy their 1333/CL11 Apple branded ram modules. Won't do that cuz I already have their non apple branded modules working on mine without a hitch. So , can anyone plz shine a light on whether the 1866 is worth getting? Will it work on my MBP?