Windows – SSD in external USB 3.0 closure not recognized as SSD

external hard drivessdwindows

I've brought an SSD and external closure that supports UASP and USB 3.0.
The drive is recognized and the speed is ok. But the drive is recognized as normal hard drive by Windows (8.1). I.e. when I try to optimize the SSD volume it begins to defragment it instead of issuing TRIM command.

My question is what characteristics should an external hdd closure have to have to allow Windows to recognize it as real SSD drive? Is it possible at all with USB 3.0 interface or I need an eSATA interface?

Best Answer

This is what wikipedia says about the Trim command :

The TRIM command specification is being standardized as part of the AT Attachment (ATA) interface standard, led by Technical Committee T13 of the International Committee for Information Technology Standards (INCITS). TRIM is implemented under the DATA SET MANAGEMENT command (opcode 06h) the draft ACS-2 specification. The ATA standard is supported by both parallel (IDE, PATA) and serial (SATA) ATA hardware.

Conclusion : TRIM is only for drives connected via IDE and SATA variants, so does not apply to USB.

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