ssd via usb3 questions: details on performance and life decrease extent without trim

paul13

Commendable
May 21, 2016
19
0
1,520
So I am looking to use an ssd via usb 3.0 enclosure to load Windows 10 to go and use with an otherwise decent work pc (hdd + restricted os rights are a pain). As I understand, trim canot be enabled/used in such case, so the questions in order of importance are as follows:

1) how much of a performance drop does an ssd experience with trim off in the average to worst case scenarios? It feels like there hardly is any info on the topic anywhere :( in other words, is it crippling enough to make such usage next to useless.

2) how (much) will lack of trim affect the ssd lifespan?

3) (bonus) is usb 3.0 enclosure performance more a % of the drive quality (buy better ssd to get considerably better result) or hard capped (older ssd with half the speeds we see these days acceptable since it won't go over certain limit) ? I do understand that the usual 520/520 numbers are cut off considerably, more interested in the part where the extreme benefits over hdd show, ie random read/write

Any links to articles/tests/research on these would also help.

Thank you in advice for any details you can throw at me.
 
Solution
Windows generally will not install or boot from an external HDD, except with extreme difficulty. You also won't be able to move it between PCs due to licensing, if that was your intention.

You will see hard caps on I/O performance (very slow; IIRC USB is synchronous, so you can't have more than one I/O event waiting at a time, and the latency per I/O is going to be worse than SATA). How bad, I don't know.

Does your work know about this? Using business property for personal reasons is a great way to get fired, and they've probably locked down the BIOS if they're not completely stupid. If you absolutely need admin rights to do something for work, convince your boss to go with you to IT and ask nicely.
Windows generally will not install or boot from an external HDD, except with extreme difficulty. You also won't be able to move it between PCs due to licensing, if that was your intention.

You will see hard caps on I/O performance (very slow; IIRC USB is synchronous, so you can't have more than one I/O event waiting at a time, and the latency per I/O is going to be worse than SATA). How bad, I don't know.

Does your work know about this? Using business property for personal reasons is a great way to get fired, and they've probably locked down the BIOS if they're not completely stupid. If you absolutely need admin rights to do something for work, convince your boss to go with you to IT and ask nicely.
 
Solution
I'll address only that portion of your query re booting a MS OS from a USB external HDD/SSD.

Ordinarily directly installing the OS onto the disk connected as a USB device will not result in a bootable drive. The only reason I state "ordinarily" is that there have been a considerable number of reports over the years by this one or that one purporting to overcome this inability through some rather tortuous programming modifications that could be undertaken by an end user. They've never worked for us at least in any reliable way.

However...
A number of disk-cloning programs possess the capability of creating a cloned drive containing an OS and that cloned drive will boot as a USB-connected device. The disk-cloning program I routinely use - Casper - has this capability. It works virtually 100% of the time where a "generic" PC is involved; however we have found some OEM machines will sometimes balk at booting a cloned drive.