MacMini M1 and slow TB3 external SSD drives

[XRayAdamo]

Hello everyone.
Since I bought 16Gb 512Gb MacMini I found that my external SSD Thunberbold 3 drive is working very strange. Speed for write and read is jumping between 500 and 2100. Same drive tested on my Macbook Pro Core i9 shows constand mac speed with no drops.
So, is this a my device problem or this is M1 problem? A lot of people already complained about slower USB-C speeds on M1 machines so this might also be a problem.

Provided screenshot shows current speed. It is very "jumpy" Who has TB3 external drive and M1 Mac, can you test it?

 

[Peter118]

I also own a Mac Mini M1 16GB/256GB. I bought a Jeyi Thunderbolt 3 M.2 NVME enclosure with a 1TB Samsung EVO m.2 SSD. Speeds are constant and are :
Read - 3100MB/s
Write - 2100MB/s

Very happy with it.

 

[antipodean]

I saw the same thing as the OP. My M1 mini (16GB/1TB) with Pluggable 1TB T3 SSD shows read and write speeds that jump between 900 MB/s and 2100 MB/s. Similar behaviour when connected via my CalDigit TS3+ TB3 dock.

On my intel MBP (13" 2020), the same SSD sustains speeds around 2300 MB/s until its internal buffer is expended and speed drops to around 1000 MB/s.

The internals on both machines are faster. The M1 easily clears 3200 MB/s write, while the 1TB internal in my intel MBP is more like 2700 MB/s.

I have quite a few USB-C SSDs and none of them exceed 900 MB/s.

 

[XRayAdamo]

I thunk we can close this topic. It appears that my Yottamaster is actually is the reason not working properly so now I probably will look for better enclosure. 20 minutes test on Intel based and same drops of speed