4TB Extreme Pro, only 1,000MB/s speeds? (MacOS/APFS)

Legacy SanDisk Products Extreme Pro Internal SSD
1

Brand new drive (Extreme PRO Portable SSD, 4TB), freshly formatted to APFS, Mac Studio, Thunderbolt/USB4, tried cable both ways, different ports on my Mac Studio, and I’m topping out at 1,000MB/s for my speeds.

Am I missing something? Any firmware update? Tried a few different speed tests, all the same speeds.

2

Hi @sandisk3,

Please contact the SD Technical Support team for the best assistance and troubleshooting:
https://kb.sandisk.com/app/ask

3

Have you sorted it out? If not, these steps should help.
1.Use the First Aid feature of Disk Utility, it can check the errors on that portable hard drive and repair the detected minor errors of directory structure.
2. Check what programs are using the external hard drive in Activity Monitor and quit some programs.
3. Format the portable hard drive on Mac to completely erase and reorganize data.

[ Further read: Slow External SSD and HDD on macOS Ventura ]