Mac Mini M1 - SLOW EXTERNAL HARD DRIVE SPEED

well 35 to 40 MBits/s is pretty much the sustainable transfer rate one can expect from usb-2

if it was me then I would test it with another computer to verify if the device was running in usb2 mode

and or if your mac was causing it to run in usb2 mode

• Defragment your disk drive.
• Run a check disk scan.
• Look for damage to the case or the drive itself.
• Check the cables, replace them if necessary.
• Too much disk activity.
• Check your drive and PC for viruses and malware.
• Disable Windows indexing for faster performance.

What USB 3.0 bays (enclosures)?

How are you measuring the speed?

FWIW I have a few Sabrent USB 3.0 2.5 tool free enclosures with PNY and Crucial SSDs in them and they preform at the full 6G speed on both my 2012 Mac Mini’s and 2018 Mac Mini.

logicpro7composer wrote:

......

It makes sense to upgrade at least to the new Samsungs T7 which go up to ø 1200 MB/s and using a T bolt enclousure.

....

The T7 is a completely integrated USB device and cannot be put into a TB enclosure, if I understand what you said correctly.

Now if you were talking about a T7 or a TB enclosure then that is different.

As far as the T7 and M1 Macs, you will disappointingly only get the data speeds of a 5Gb/sec connection instead of the 10 Gb/sec speeds that Samsung claims. There is an issue with Apple's implementation of the USB-C ports and Samsungs implementation that limits the transfer speeds.

As far a using a Thunderbolt3 enclosure with an NVMe SSD, with the right combo of card and enclosure you can achieve real read/write speeds in the neighbor hood of 1200 MB/s to 2400 MB/s. The reason I say right combo, despite all manufacturer claims, some cards can perform well in a given enclosure while others won't and the combo may work well on Macs and not PCs and visa-versa.