Hi,

I have to use a proprietary tape backup software from 1997 to copy a couple 100GBs that will only work with a storage device in Multi-Word-DMA mode - MDMA mode (0-2). I have to use SATA SSDs to copy the backup tapes to.

After connecting drives I change the mode of the SSD (2nd physical drive in computer) with the the following command in terminal:

hdparm -d1 -X mdma2 /dev/sdb

That works and puts my backup SSD drive in MW-DMA2 mode (max 16MB/S transfer rate). Then attempting to read/write to the drive freezes the machine, just copying a 50MB file to the drive in the terminal as a test, the tapes are not even connected at this point.
All PIO and UDMA modes work, but any MDMA mode will cause a hard lock and crash the SSD when read/written to, I have to turn off power.

Is this a bug in Linux Kernal (same happens in Ubuntu,Debian,Zorin and Suse). I find it hard to believe SATA SSDs no longer work in any MDMA mode (they advertise this as a supported mode - but they have dropped SWDMA modes).

I have tried different motherboards and different brands of SATA SSDs to rule out hardware differences.

No experience, but a quick search found this - looks very relevant.

After reading the link you posted I connected an SATA SSD to a Windows 11 computer. After changing some settings in the registry I forced the SSD to MW-DMA2 mode. Then i coped around 1GB of files, read them back and hash checked the files, it worked.
So this is a bug in Linux, simply an SATA SSD will not work in any MW-DMA mode and crash the OS when read/written to (all PIO and UDMA modes work).

Any Linux Guru's out there who can help with this.