fportela wrote on 2020-05-23, 00:35:
SATA and Giga Ethernet are probably the best choices. M.2 is expensive yet and excessively fast for this kind of application.
For what it's worth, M.2 is just a form factor. Most M.2 drives are SATA and they are often about the same price as their 2.5" SATA equivalents. You're probably thinking of NVMe drives which are normally found in M.2 form factor but instead use the PCI-Express interface rather than SATA.
For example:
2.5" SATA drive
M.2 SATA drive
Low end M.2 NVMe drive
Higher End M.2 NVMe drive
NVMe can be significantly faster but at the moment the performance makes almost zero real world difference for home use because SATA SSDs are already plenty fast enough. It's been suggested that the use of NVMe SSDs in the next generation of consoles will allow programmers to harness the speed so that loading is smoother\faster, but only time will tell.
For retro PCs though, NVMe has no practical use. Any SSD is going to be several times faster than the interface being used to emulate a CD-ROM.
That said, if adding an M.2 SATA slot along side SATA ports doesn't add much to the expense of any of these retro-upgrade type devices, I would definitely want an M.2 slot. You can buy low capacity M.2 drives pulled from old netbooks for only a few bucks a piece online. They would make amazingly compact and fast drives for retro PCs, it just stinks that there are so many adapters needed to use them as IDE\PATA drives. I use a 16GB M.2 drive (about an inch long) as the primary drive in my 98SE tester system, but it has to be on 3 adapters chained together to make it work. 🤣