OK... here's why I ask about TRIM being "broken" (as in "does absolutely nothing at all") on the 970. What, exactly does that sentence above mean?
The original issue is here:
It says: " On several controllers, such as Samsung, where the deallocation process is relatively slow,
this timeout can be reached very quickly. (snip)
One way to workaround the problem is to increase the timeout to an extremely high value, which at the cost of slow boot times (extra minutes)
will ensure that all the blocks are trimmed. "
IOW, at the cost of a slower boot time, TRIM will proceed correctly.
However here:
https://github.com/dortania/bugtracker/issues/192 (which links to the original issue)
it describes various SSDs, saying "Working with TRIM broken (can be used with TRIM disabled, at slower boot times, or as a data storage): (snip) Samsung 970 Evo/Pro"
It appears to me that there is confusion stemming from a single comma [after 'disabled'], and thus how you read that sentence.
Sentence: Working with TRIM broken (can be used with TRIM disabled, at slower boot times, or as a data storage):
reading #1: can be used with TRIM disabled, (which will mean you have slower boot times) or as a data storage
(
two possibilities: disabled or data)
reading #2: "can be (a) used with TRIM disabled, (b) at slower boot times, (c) or as a data storage
(
three possibilites: disable, slow, data)
Reading one means "TRIM does nothing at all except slow you down" (IWO "TRIM is totally broken")
or
reading two means "you can disable TRIM,
OR you can accept the slower boot times to get it to work,
or you can use it just for data"
Reading number TWO
matches the original description of the issue. Reading #1
does not match the original issue.