I am about to upgrade my MacBook Pro Late 2011 to an SSD, finally giving in to temptation. I was wondering what the lifespan for the Crucial M4 would be, and I know it is 72 TB of writing. However, will it actually last that long? What is the probability of it failing before that? ... I hope it was not a bad buy as I have to forward it to my country from the US and that incurs great cost. And I noticed that my computer writes to hard disk (from Activity Monitor Data Written/sec in Disk Activity) at a rate of about 11 MB/s when it wakes up from sleep. Why is this so? Will it happen after I upgrade to SSD as well? Does that shorten the disk lifespan? What causes great writing to disk other than downloads and how to minimise that? I love downloading and hope that upgrading to SSD does not force me to reduce my downloads. Thanks! P.S. Hoping for a PowerNap tweak for older models when Mountain Lion comes out ... if possible. Edit: I forgot to ask TRIM or not from users of Crucial m4? How does it affect speed and durability? Thanks! And is this reliable data? http://silverdire.com/2012/06/11/reduce-ssd-writes-mac-os/ What does disabling hibernation do?