Hi, The past few weeks I've noticed how sometimes my MBP will just crawl to a halt. I rarely get a beachball, but clicks can take 5 seconds to register, Spotlight won't respond, Safari won't open a new tab quickly, Mission Control takes forever to activate etc. The specs are 15" early 2011, 8GB RAM (aftermarket), 750GB 5400rpm HDD, 2.2 Quad i7 and the AMD 6750M. Interestingly, since (December? Ish) I've verified my disk three times, and twice it came back as corrupted and needing repair with the recovery partition. Also, I get kernel panics about once a week, but almost always when I'm not using it for some reason. RAM often goes into 1-2GB compressed after a day of normal use - not sure if that's good or bad. The system is also migrated from probably around 2003 - I haven't really ever done a clean install since OS X came out. Not really sure what the culprit is here. It happens fairly intermittently - some days it works fine, others it's almost unusable. A lot of the time, I switch to our lesser specced 2010 iMac (3.06 i3) as it seems a lot faster! Any help would be much, much appreciated. Thanks. ---------- Forgot to mention - it takes over two minutes to boot as well.