A couple of days ago, while I was SSH'ing into my main desktop, I suddenly heard less noise coming from the room and my connection froze up. I walked over, clicked the power button, and... nothing.

Several weeks of running full-tilt with Rosetta@Home and GPUGRID were just too much for the cruddy "500W" power supply that I had never gotten around to replacing when I upgraded the motherboard to a Ryzen 7/1700 a few years ago. I did an autopsy on the power supply to find it chock full of Jun Fu capacitors and some the wimpiest heat sinks I've seen; I suspect that PSU would have difficulty keeping up with a 250W load. I had to run over to one of the few remaining freestanding computer shops in the area (fortunately, open for business since people need work-from-home supplies!), and wound up getting an 850W Seasonic, which ought to have enough headroom for a beefier GPU should I upgrade that as well. Bonus: my UPS reports about a 3-4 percentage point drop in electrical load with BOINC cranking away.

The moral of the story: Make sure your power supply is up to snuff!

The moral of the story: Make sure your power supply is up to snuff!

General rule of thumb, the load should be 75% or less of the PSU's rated capacity. Allows some head room for instantaneous loads, and for really hot days.
So a 850W PSU is good for a 640W sustained load (most efficient is generally a load of around 50% of the rated output).

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Grant
Darwin NT

A couple of days ago, while I was SSH'ing into my main desktop, I suddenly heard less noise coming from the room and my connection froze up. I walked over, clicked the power button, and... nothing.

Several weeks of running full-tilt with Rosetta@Home and GPUGRID were just too much for the cruddy "500W" power supply that I had never gotten around to replacing when I upgraded the motherboard to a Ryzen 7/1700 a few years ago. I did an autopsy on the power supply to find it chock full of Jun Fu capacitors and some the wimpiest heat sinks I've seen; I suspect that PSU would have difficulty keeping up with a 250W load. I had to run over to one of the few remaining freestanding computer shops in the area (fortunately, open for business since people need work-from-home supplies!), and wound up getting an 850W Seasonic, which ought to have enough headroom for a beefier GPU should I upgrade that as well. Bonus: my UPS reports about a 3-4 percentage point drop in electrical load with BOINC cranking away.

The moral of the story: Make sure your power supply is up to snuff!

Ha!
I laugh because I know it's not funny. This is the kind of thing you only experience once - because of the terror-factor in my situation.
My previous one came as part of a shop-bought PC and may only have been 330W. No branding. No-one would admit to making it.
I went to an EVGA 750W 80+Gold fully modular. If I'd looked above my arbitrary price ceiling, for 2GBP more I'd have chosen the 850W, but no problems since.
Seasonic had a very good rep at the time I was looking so you can relax. And maybe peel the cat off the ceiling.

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Yup, years ago at my office, we got a bunch of white-box PCs that had the infamous Deer power supplies. Those didn't hold up well - I remember powering up one of the Slot 1 Pentium II boxes to hear a loud fizzing sound and see a cloud of smoke come out from the power supply. Not only did the PSU fry to a crisp, it took the motherboard and HDD with it.

I've had a Seasonic in a Mini-ITX system that I use for Asterisk, and it's been soldiering on for quite a while now. My Corsair-equipped boxes have also held up well.

And, the hilarity continues. I un-mothballed another old box and fired up BOINC. Things were going smoothly when I went to bed last night, but when I woke up this morning I discovered that the system was going haywire, with 160+ GB (yes, gigabytes) of goodness in /var/log and the system running at a crawl. I fired up memtest86+ and, lo and behold, discovered that I had a bad stick of RAM. I told it to report the error in badram format, set GRUB_BADRAM in /etc/default/grub accordingly, ran update-grub, and rebooted. Now it has about 7 GB of RAM instead of 8, but I'm not spending money on what is now an obsolete system, unless it's to replace the motherboard and CPU along with the RAM.

We'll see if I have to drop a task or not, but I think 7 GB should be enough to run four Rosettas.

My mighty 4GB Atom X5-3850 PC Stick can usually run 4 with 4 GB RAM (WIN10P). But today I noticed "waiting for memory" even when no tasks were running. Boosted the swap space, checked the settings, nothing would budge the "waiting for memory" tasks into running, so I aborted them so they could run elsewhere. Apparently most R@H tasks are under 1GB, but some are much bigger? No problems on my much beefier desktop PC, except one of the fans sounds a little strained. I thought I'd run the Atom 24x7 because it barely needs power.

Apparently most R@H tasks are under 1GB, but some are much bigger?

At present, up to 3GB. There are soon to be ones that may need up to 4GB of RAM.

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Grant
Darwin NT

So far, so good on isolating the bad RAM. The box has been cranking away for 10 days now without a hiccup. There was one reboot for a kernel update, but that was intentional. I haven't noticed any problems with losing that last gigabyte.

Still, it's time for me to save up for a new Ryzen board - and ECC RAM. I have no regrets about picking ECC on my last Ryzen build (no reported memory errors according to edac-util), but the A10 APU in the system with the bad RAM doesn't support ECC.