Sierra, High Sierra, and trim for SSDs

[serr]

If you had a SSD that did not require trim enabled in the past, you'll want to check that again under OSX 10.12 and 10.13 (Sierra & High Sierra). Apple turned something on starting in 10.12 and you may need to enable trim if you had it disabled before. (Or perhaps they turned something off?)

Apple defaults to trim disabled for any 3rd party drives they have not qualified themselves. If I understand correctly, some Linux installs will use 'queued trim' which is not supported by some SSDs (like the popular Samsung). I don't think this is ever an issue under OSX or even Windows.

If you have a Samgsung or other 3rd party SSD and recently installed OSX 10.12 or 10.13, check your drive speeds. (Or if you disabled it out of caution for your Apple supplied drive too.)