I'd definitely recommend against buying second hand GPU from crypto miners. They have been worn out running 24/7 for years.

If it's selling for $30 I don't say, but I've seen them going for a fair bit of the original price.

The thing is I've never worn out a piece of equipment in 25 years of computer enthusiasm. I've had some DOAs and infamous equipment (say Deathstar) but never failures even second hand equipment. Is that different for 24/7 max power draw or is it just YMMV (and usually will still work)?

I've seen every single piece of equipment worn out over the past decades except the CPU.

Hard disk and GPU are the worst in my experience. They have the shortest lifespan and they're the most impactful when they die. Hard disk die suddenly destroying all data, self explanatory. GPU die slowly, progressively having rendering error then crashing the system erratically.

I've taken 3 GPU to their grave between my personal computers and my family's.

To limit my spending I have a personal policy where I don't upgrade my GPU until it dies (I don't generally play the latest AAA games on my PC) and with just one outlier since 2004 I've had a new one about every 4-5 years. I've actually never had a CPU fail but I've had several HDDs die.

Nah if your HDD is dying it’s either your task really demands it OR you’re not cooling them enough.

If your GPU is dying it’s VRAM or VRM is failing under high heat. Manufacturers cut fan speed to cut fan noise until warranty claims increase substantially so they never provide sufficient cooling at stock settings.

Rackmount servers don’t sound like jet engines for no reason. Things fail if you don’t do that.

I've had hard disks fail in a PVR setup (heavy load), I've had memory fail, I've had motherboards fail, I've had power supplies fail, and I've literally typed laptop keyboards to death in ~2 years. I'd be utterly unsurprised about a GPU failure.

The best case scenario is "selling it because I'm buying a new one", the worst case scenario is "selling it because it's starting to flake out", and "selling it because the warranty ran out" is not much better.

Storage fails all the time. Cables, power supplies, UPS, monitors, keyboards, mice - I have a graveyard in a cabinet.

Also motherboards who's capacitors dry up; connectors that develop faults.

This is of course leaving out devices who's firmware get exploited and become poison (routers, USB devices with malware)

It's both.

The ymmv is always big with electronics. I.e. my second last graphics card (gtx970) died within 2 yrs. But the aging effect from running 24/7 under high load is very real as well.

The high temperatures of permanently running on full power just wears it down

Besides mechanical parts you can still see failure from weary chemical components (capacitors, easily fixed), solder joints (fix depends on the joint. BGA chips aren't easy to fix) failing due to cycles of thermal expension and retraction or water damage, and lastly electromigration (the real unfixable damage, it usually happens from overvoltage/overheat).

At worse you might need to spend 20 bucks to replace tired fans.

Mining GPUs run undervolted without powercycling. They're fine.

Eh, I mined on some GPUs for ~a year. They're all still running today in various family members' PCs. Admittedly I was mining Ethereum where the main goal was to undervolt and underclock as much as possible while maximizing the memory clock.

How did you cool them? I mean, didn’t you find stock fans way too weak especially had it been in a “quiet” PC?

All the cards I had were "aftermarket" cards with better coolers (7x dual fan GTX 1070s & Pentium G3258 running Gentoo). It wasn't silent but it really wasn't that noisy. After unvolting and underclocking the GPU core, and overclocking the memory, they ran at ~60C under constant load.

I gave three of them to family members and sold the other 4. I was absolutely upfront in my eBay listings of their history.

I picked up a refurbished Vega 56 last year for a great deal. I suspect it was a mining card. Seems to work fine.