Running SSD via USB 3 (UASP) speeds improvable?

[Steelbom]

Hi,

I've got a 500GB Samsung 850 EVO. It's inside a Transcend USB 3 (UASP) enclosure, and it's split into two 245/255GB partitions. Booting into Windows 10 Pro via UEFI on my Mac. I've made a bunch of SSD optimisations such as turning off Prefetch, Superfetch, and some other things.

In Samsung Magician I get 400MB/s seq read/write, but only 35K IOPS random read/write. It's not too bad, but I was hoping for a little more. (Sata II got me 40-50K IOPS in a different computer with a 250GB model.)

Is this the best I can get over USB 3?

Appreciate any input. (Computer is late 2013 27 iMac, supports USB 3 + UASP)

 

[=Wendy=]

USAP doesn't appear to scale above a queue depth of 4, and it doesn't scale at any queue depth as well as SATA does. But even then, 35K IOPS should be more than enough for a good experience.

Also, the max sequential transfer rate I've seen from USB3 was around 420 MB/s, so you're not that far off that rate.

 

[coercitiv]

I've made a bunch of SSD optimisations such as turning off Prefetch, Superfetch, and some other things.

What gains did you observe after disabling Superfetch & Prefecth?

 

[Steelbom]

USAP doesn't appear to scale above a queue depth of 4, and it doesn't scale at any queue depth as well as SATA does. But even then, 35K IOPS should be more than enough for a good experience.

Also, the max sequential transfer rate I've seen from USB3 was around 420 MB/s, so you're not that far off that rate.

Ahh interesting, good to know thanks. I guess I will switch to a Thunderbolt enclosure in the future. If only I could find one like the OWC Mercury On The Go but without a drive. Too expensive as it is.

Yeah definitely, things seem much faster. And yes the transfer rate is around that number. But for me the random numbers are more important.

What gains did you observe after disabling Superfetch & Prefecth?

I didn't perform any tests, however the first run of the benchmark I think I got around 25-30k on read, so it may have helped (among other things as well. I just Googled SSD optimisation Windows 10, more or less.)

 

[tweakboy]

Your lucky if you get 180mbps
gl