While Samsung previously indicated that queued TRIM works for Samsung 860 SSDs on Linux, with only older Samsung 840/850 drives being barred from queued TRIM usage, this has now been proven to be incorrect, and further oddities have been added for the Samsung 860 and 870 series SSDs on Linux.
Queued TRIM has been enabled for the Samsung 860 in Linux kernels for the past three years, however it has been disabled for 840/850 drives. However, many Linux users are still having problems with the 860 and 870 disks.
Queued now disables queued trim by putting the Samsung 860/870 series to the blacklist via the Linux kernel block subsystem. "A substantial number of customers are still experiencing issues with Samsung 860 and 870 SSDs when used with Intel, ASmedia, or Marvell SATA controllers, and all reporters indicate that these issues disappear when queued trims are disabled."
It's considerably worse if you use a Samsung 860/870 with an AMD processor. When utilizing an AMD chipset, a new blacklist entry will completely block native command queuing (NCQ) for the Samsung 860 and 870 SSDs. Disabling NCQ on certain drives will have a negative impact on the performance of the affected systems.
Notes on the commit "Many users have reported that the Samsung 860 and 870 SSDs have numerous difficulties when used with AMD/ATI (vendor ID 0x1002) SATA controllers, and that the only way to prevent these issues is to entirely disable NCQ. When NCQ is disabled for Samsung 860/870 SSDs, independent of the host SATA adapter vendor, I/O performance is degraded, even with well-behaved adapters. Introduce the ATA HORKAGE NO NCQ ON ATI setting to forcibly deactivate NCQ exclusively for ATI adapters, limiting the performance effect."
In other words, Linux users should aim to stay away from the Samsung 860 and 870 series SSDs. These changes are currently being included into the mainstream Linux kernel.
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