Sudden decrease in SSD speed. (Crucial M4)


macrumors 6502
Original poster
Nov 27, 2011
Long Island/North Jersey
Hey guys and gals, I recently purchased a Crucial 256gb SSD when they were on sale a few weeks ago and at first the performance was awesome. But I just shut down my computer and when rebooted it started to act a little funny (my wallpaper was reset to factory) so I ran a disk speed test and the test showed that it is now writing 100mb/s slower than it was just a week ago! I understand that speeds will always vary a little however an almost 50% decrease is unacceptable to me. I hope I'm missing something as I want to get what I payed for and right now its not. Thanks a lot for anybody with any insight on the problem.


Staff member
Jan 23, 2005
Are putting it to sleep immediately after use perhaps? The M4 uses a method of garbage collection in its controller that runs during system idle time AFTER a lot of write activity. Try disabling sleep and just letting it sit running a couple hours and see if that restores write performance.

Read over the TRIM section of this review of another drive for an overview of what is going on.
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