You Do Not Need to Enable AHCI to Use TRIM for SSDs

[Petros_K]

I'm encountering many people suggesting if you don't have AHCI enabled in BIOS for your SSD you won't be able to use TRIM.

I have a computer that's running Windows 10 but it's an old Dell Vostro 410 and the BIOS options for storage are only IDE and RAID. I have it set on IDE and know the system has TRIM and "optimize" enabled for the SSD. It doesn't need to have AHCI. From wikipedia:

"Windows 7 initially supported TRIM only for drives in the AT Attachment family including Parallel ATA and Serial ATA, and did not support this command for any other devices including Storport PCI-Express SSDs even if the device itself would accept the command. *It is confirmed that with native Microsoft drivers the TRIM command works on Windows 7 in AHCI and legacy IDE / ATA Mode. Windows 8 and later Windows operating systems support the unmap command for devices that use the SCSI driver stack, including USB Attached SCSI Protocol (UASP). Windows 8.1 and later Windows operating systems support the TRIM command for NVM Express SSDs."

https://en.wikipedia.org/wiki/Trim_(computing)

I think people are getting the impression if you're using older equipment you can't properly use an SSD with it.

 

[hotaru.hino]

To further point something out about AHCI:

The specification describes a system memory structure for computer hardware vendors to exchange data between host system memory and attached storage devices.

It doesn't describe how the OS is supposed to talk to the drive in terms of commands. To put it in another way, the data your keyboard sends to your computer is independent from the interface it's using. That is, USB or Bluetooth are simply carriers.

 

[BFG-9000]

While the Vostro 410 is ICH9R and thus employs a chipset that definitely supports AHCI (Dell just didn't provide the BIOS entry for it), I can confirm that chipsets that don't even support AHCI at all such as ICH7 can indeed work fine with TRIM.

TRIM does not work in RAID mode until Haswell chipsets (unless you use a modified option ROM such as Fernando's) so IDE mode is probably preferable over a single-drive RAID "array" for SSD use. However be sure to look for an "Enhanced" mode setting somewhere in the BIOS to enable SATA300 speeds instead of the ATA100 speed of "Compatible" (note however that device manager may still report 100MB/s UDMA5 even though benchmarks show the faster speed is enabled). Things like Native Command Queuing obviously don't work without AHCI, but if you think about it, that shouldn't be too useful for a SSD.

 

[kerberos_20]

controller needs to pass trim commands, some will work, some not

 

[hotaru.hino]

controller needs to pass trim commands, some will work, some not

If a SATA controller, even in IDE mode, drops ATA commands, that's a terrible controller and should be burnt to the ground.

That's like if your router is hardwired to drop packets if you're trying to connect to Google or something

 

[kerberos_20]

If a SATA controller, even in IDE mode, drops ATA commands, that's a terrible controller and should be burnt to the ground.

That's like if your router is hardwired to drop packets if you're trying to connect to Google or something

https://docs.oo-software.com/en/oodefrag-20/extras/trim-incompatibility-20

here some deeper dive