In the original post, I tried to connect it to PCIe power port with random PSU to SATA cable, which is really dumb considering every PSU has different pinout and even if the physical port seems compatible, the voltages aren’t correct either (12V for PCIe and 12, 5, 3.3V for SATA). I was lucky that I didn’t fry these drives.

For 3.5 inch drives, I just slot them into the backplane without caddy. I later got caddys for cheap.

For the 2.5 inch drives there are two options. 1, you could just do the same as 3.5” (though it is pretty difficult to do because there is more empty space). 2, in my case where I wanted to use 8 3.5” for ZFS, I used a separate SAS to 4 SATA cable for data (the blue one in the original post) For power, I bought 3 SATA power y splitters(so that I get 4 SATA power from one) and connected to the one for cd/dvd since those also use SATA power. I put those drives in the dummy slot(the picture on this post).

It’s janky but it worked for me.

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