External NVME - Slow Write Speeds

[-paradox-]

Hi!

I just bought a Fledging Shell external NVME enclosure (https://fledging.net/products/shell-thunder) connected via Thunderbolt 3, equipped with a Western Digital SN750 4TB (brand new; recommended by Fledging Shell).

I've tested it with my 2019 iMac (Mojave) and 2018 Mac mini (Catalina) (different cables, different ports), but results stay the same: my read speeds are as high as expected (2400MB/sec), but write speeds are always only between 500MB/sec and 900MB/sec (empty drive; no difference if formatted ExFat / AFPS / MacOS).

Is there anything OS related that could be causing this problem (e.g. TRIM support off) or do you think it's hardware related? Any ideas what it could be (enclosure or NVME)?

Many thanks!

 

[moonwalk]

I have the same Western Digital SN750 4TB drive in an Acasis NVME enclosure, write speeds getting about 850 to 1,200MB/s (average about 1,000MB/s) on an M1 mac mini. Reading other posts it seems like any NVME drive above 2TB has a slow write speed. Some blame the TB controller. I expect to soon have a Caldigit element hub, and hopefully that improves write speeds. We can also hope Apple can fix this with OS updates, if enough of us complain. Here's another thread:

External TB3 NVMe SSD - only 800 MB/s write speed

Change test file size in Blackmagic and AJA, sometimes variation forces rewrite of test files.

forums.macrumors.com

 

[moonwalk]

And this:

USB on M1 Macs isn't actually 10Gb/s? (Also definitely not USB4)

Has anyone found a solution to getting SSD's such as the Samsung T7 (which are benchmarking around 800 Read / Write on the Intel MacBook Pros), running at full speed on M1 Macs? [Without having to carry around a heavy Thunderbolt dock) My results here: T7 connected to directly Intel 16-Inch...

forums.macrumors.com

 

[-paradox-]

Thanks!
That’s very disappointing and weird...I should’ve just gone for the Sabrent rocket external TB3 drive
The only thing that worried me was the bad reviews about their costumer service, but at least the drive would’ve delivered great speeds...

BTW: I have the caldigit TB3 plus if that’s what you’re referring to and speeds are even a bit slower when the drive is connected to it (600MB/sec).

 

[moonwalk]

Thanks!
That’s very disappointing and weird...I should’ve just gone for the Sabrent rocket external TB3 drive
The only thing that worried me was the bad reviews about their costumer service, but at least the drive would’ve delivered great speeds...

BTW: I have the caldigit TB3 plus if that’s what you’re referring to and speeds are even a bit slower when the drive is connected to it (600MB/sec).

No, Caldigit's new TB/USB4 hub is called the Element. Time will tell. Also, I'm not sure the Sabrent rocket will deliver more write speed. The determining factor is the SIZE of the drive. All 1TB MVNe drives seem to have fast writes speeds.

Thunderbolt 4 | USB4 | Element Hub | CalDigit – CalDigit

www.caldigit.com