This is commonly addressed by relocating any other retained data within the block, so enabling that block to be erased ready to receive the new data. To avoid incurring such overhead, the operating system can maintain a list of blocks which are no longer in use, and once a block becomes unused, it can inform the SSD’s firmware that the block can now be re-used.
#TRIM ENABLER MAC OS FREE#
This allows the SSD controller to erase that block, and maintains good write performance even under heavy use with limited free space. Operating systems, including macOS, gained TRIM support around 2010, but this has proved quite complex and varied by type of SSD, and by file system.
#TRIM ENABLER MAC OS SOFTWARE#
While generally available for software RAID systems, except AppleRAID, the TRIM command is normally not supported by hardware RAID systems.Įnabling TRIM doesn’t automatically improve performance, and in some circumstances can instead impair performance. In early releases of APFS, users who manually enabled TRIM sometimes encountered longer boot times, which have been attributed to TRIM commands being sent to the SSD during the boot process. In practice, it shouldn’t be hard to detect poor write performance on an SSD which could be addressed by enabling TRIM.
I have yet to see any reports that external SSDs in APFS format need TRIM to be enabled because write performance has deteriorated, although the default in macOS appears to be to disable TRIM support for external SSDs. Most accounts of TRIM and its support are now getting quite old, and don’t refer to file systems such as APFS which are optimised to work with SSDs. I’ve been unable to find any recent recommendation from Apple or a similarly authoritative source that TRIM support should be enabled on internal or external SSDs running the current version of APFS.įor the moment, in the absence of any better information, I suggest that it’s wise to buy external enclosures and drives which can support TRIM, but not to enable it unless you observe slowed write performance on your SSD. The command that you’ll then need to use isįollowed by restarting your Mac for it to take effect. The man page warns: “Use extreme caution when enabling TRIM, as some drives may not correctly handle the commands.”Īs far as I can see at present, looking in System Information and Disk Utility, you can only tell whether TRIM is enabled on certain SSDs, including those mounted internally or connected via buses such as Thunderbolt 3 which seem to pass this information. This is given in System Information when you select that SSD according to its connection. But no information on TRIM support is given for the most common connection for external SSDs, USB 3.1. The trimforce command doesn’t have a verb which will inform you either.
0 kommentar(er)
