On Fri, 1 Jun 2018 16:04:43 +0100, Patrick wrote:

As mentioned by 'Paul', the 3.3v is not required.

You are right!

I put in the new WD Blue hard disk and it works fine at SATA2-0 as the boot
disk (with the SATA power connector), and each of the other two disks
independently work fine as ancillary disks - but until I pick up the cable,
I'm one power cable short.

Now I'm just curious if it matters that I pull off the SATA data cable from
the one disk that doesn't have power?

I've been swapping both connectors each time I need data from those two old
disks, but since I have plenty of SATA data cables, would it be "safe" to
just leave the SATA data cable on the one disk that doesn't yet have a
power connector?

I googled and didn't find anyone that reported a problem but I'm just
asking about your experience where I already know it's "safer" to NOT have
the data cable without a power cable.

But I was just wondering if anyone knew if it's literally safe to have just
the data cable on a disk?