SSD in an external USB3 enclosure

Computer Help and Discussions Hardware
1

I'm thinking of putting a 120gig SSD in a USB3 external enclosure instead of buying a new high capacity USB flash drive.

Just wondering if anybody had any thoughts on this - good or bad.

My main concern is that I could put in a 500gig HDD for half the price but want to have the device as fast as a top-of-the-line USB stick.

(I used to use Corsair Survivor GT's and now use Lacie XtremKeys)

So does using the USB3 controller make whatever sits behind it a bit pointless.

Or can I expect the same through-put as a SATA3 controller connected drive.

2

Dunno about all that, but I hear that USB3 chipsets do not support the TRIM command, which might be a further consideration. Although the SSD and the O/S might support TRIM, and the TRIM command is indeed issued, it never gets through to the SSD. I can't find I definitive yes/no on this though.

3

if you are right about that, i wonder how (or if) the TRIM command works on USB3 flash sticks.

but, in all honesty, a lack of TRIM won't be a show-stopper, as with my USB sticks, this SSD in an enclosure idea is for the unit to only be plugged in for backups and to put in clients PC's to run software off.

so it's only plugged in like 5-10mins at any one time. (not sure how much time a TRIM takes to complete). and it'll be a half dozen different PC's each day, all various Win versions.

(but I can run an Optimise on my Win8 rig once a month or so for any SSD housekeeping)

4

I don't think that TRIM works on flash drives at all. It's something to do with the internal USB/SATA bridge - I think. You could try TrimCheck, at https://github.com/CyberShadow/trimcheck/ if you have an idle moment or two. It's probably not worth worrying about, more interest than anything else.

5

Well, as a suck it and see exercise, I got the parts today.

I've put an Intel 520s 120gig SSD into a Zalman USB3 enclosure and so far all seems very well indeed.

Speed is the same as the Lacie USB3 64gig (which is about to be RMA'd - hence the 2.5" enclosure experiment).

So I'm probably not hitting the dizzy heights of SSD speeds but I'm better off than HHD speed. And all I was after is USB3 speeds in a form factor that hopefully will survive longer than my track record with flash sticks.

6

The probability is that your USB3 SSD will be doomed to crawl at USB1 speed,

because even though the interface may still run at USB3 speed,

if the TRIM command is not successfully sent through the USB interface then the SSD firmware will NOT erase the "deleted " LBA until Windows reuses that LBA.

Until TRIM was invented the SSD accumulated redundant deleted files,

and free space was eroded and the SSD speed went downhill.

7

I'll be keeping a close eye on the speed for the next few weeks.

My backup software shows the through-put figure so I'll be using that as a guide.

The USB2 stick hovered around 30meg/s, the USB3 stick about 80meg/s and the ext SSD about 100meg/s.

The figures are a bit 'pie in the sky' as it depends on the size & number of files being transferred, but for a high-level, holistic figure, it'll do.

The main thing is it is no worse than any previous USB3 device and it ticks all my boxes I was chasing;

  • large capacity
  • high speed
  • cheaper than same capacity flash drives
  • fast read/write access times
  • shock resistance