Comment 52 for bug 1449005

Mark Rein (gimpsmart) wrote :

The exact same bug also affects the 850 PRO:
Originally, they came with EXM01B6Q, which reports "I do NOT support NCQ TRIM!".
Then, samsung released EXM02B6Q, which wrongly reports "I SUPPORT NCQ TRIM!", but of course they don't; the data corrupts if you try.

Samsung then pulled EXM02B6Q from their website for a DIFFERENT issue: The firmware update bricked many devices. But the problem is that new 850 PROs from the factory come with the new, buggy firmware preinstalled. And Samsung are not yet aware that their NCQ TRIM is buggy.

I have contacted Samsung via their regular tech support form and pointed out the NCQ TRIM bug and hopefully they will fix it. I also know that Martin K. Petersen from Oracle has contacts at Samsung and is talking to them to get it resolved in their firmware, see here:
(Full thread:

I hope Samsung will get on this swiftly, and at least release an intermediary firmware which disables NCQ TRIM until they're ready to re-add it.