Pandemic Journal, Day 475

I started tapering off of prednisone today, as planned. Unlike the first time I took it in 2016, I haven’t had any serious side effects so far (that time, I couldn’t sleep for days and took myself off before I went nuts).

The most interesting side effect has been that I’ve remembered many of my dreams – and they’ve been quite detailed. In one, I was at a carnival, waiting my turn to use a machine that painted certain parts of the body – it cost sixty cents to use, exact change only, and I can still sing the jingle it played! In another, I was very carefully cleaning a cast-iron skillet (I didn’t say the dreams were all interesting!).

The disk problems I wrote about yesterday were in my thoughts during the night last night – I’m not sure if I was awake or asleep, though. But this morning, I had a good idea about why I couldn’t copy between disks on my laptop: it was a power problem.

USB 3 Micro B plug

The portable disks I had (both the old and new) have “USB 3 Micro B” sockets and came with cables which plug into that port on the disk and into a regular old USB A port on the computer. But a modern Mac laptop only has USB C ports, so I have a hub attached to give me two USB A ports, and I plugged one disk into each port.

It Turns Out™ that my hub only provides 5 watts to be split between the two ports; neither Seagate nor Western Digital says how much power their disks need, but a little searching shows that each of them need about 2 watts when reading and 4 when writing. That’s more than the hub could supply, which explains why the disk that I was writing to clicked (as it lost and regained power) and wrote garbage to the disk.

When I plugged the disks into my Mac mini last night to try one more time, each disk could draw all the power it needed, and the copying went smoothly (and yes, I did verify the copy), so now I’m set.

If I’d had a USB Micro B to USB C cable, I would have plugged one of the disks directly into the laptop in the first place and had no problem. But Western Digital only supplies that cable with the Mac version of the drive; I bought the PC version and reformatted it, saving $15 in the process – it was a painful way to save $15!