I replaced the drive in my 2009 Unibody A1342 MacBook with an EVO 840 250Gbyte. Everything works like a dream, the best update I ever did. I never really ran it with the original drive in it so can't comment on the fan noise in a "before & after" way. I noticed however in other Forums that my MacBooks internal fans will run at 100% as a result of the SSD fit, presumably because the original HD has some sort of sensor on it. Do I need to worry? I can't say I notice the fans running at 100%, maybe there ok, maybee they are broken and I havent noticed. I have heard them cutting in and out but I can't judge whether when they do kick in, if theyre at "max chat" For info: my battery life is ok but I have noticed the base of the MacBook getting warm Anyone any ideas?