Should you use TRIM for SSD

[spyguy]

I have western digital dashboard for my ssd. It suggests running TRIM weekly. I know nothing about it. My ssd is a wd green 240gb

 

[CountMike]

Yes you can do that but windows does it automatically at set schedule. It's just a signal sent to SSD to start own maintenance process.

 

[Solandri]

TRIM is how Windows tells the SSD which sectors are safe to delete. HDDs can overwrite a 0 with a 1 or vice versa. So when they "delete" a file, they don't really erase it. They simply change the first byte of the file to indicate it's been deleted.

SSDs can't overwrite a 0 with a 1 or vice versa. They need in intermediate erase step. 0 -> erased -> 1, or 1 -> erased -> 0. This erase step is very slow (in some cases slower than a HDD). So SSDs will pre-erase deleted space during idle time. If they don't, their write speeds will plummet as they end up having to erase space just before writing new data.

Unfortunately, setting the first byte of a file to indicate it's been deleted is a filesystem-level operation. To the SSD it's just data. All it knows is that the first byte of the file has been changed. It doesn't know the space taken up by the file is safe to erase. TRIM is how the OS tells the SSD it's OK to erase that space. It isn't something you run weekly, it's something set in the OS so the OS will send a message to the SSD every time a file has been deleted. My guess is the WD message is to reset TRIM - to turn it on in case it was accidentally turned off during the week.

All that said, TRIM isn't as important as it used to be. Most modern SSDs are programmed to recognize common filesystems. So they can recognize when a file has been deleted, and can erase the sectors containing that file without needing to be told by TRIM. It can't hurt to have TRIM on, but unless you're using some oddball filesystem or have the SSDs in RAID, the SSD will probably be fine with TRIM off.