It was a few years back, but after it hit ChromeOS EOL I’m pretty sure it just got some KDE distro; I don’t think I even used LXDE. Didn’t need to do much.

I was mostly using it for web browsing, forums, spreadsheets, documentation etc. Nothing particularly strenuous.

I did have one really fun time of modifying PDF engineering drawings by opening them in Libre Office Draw which it handled kinda OK.

It did get a 240GB SSD but everything else was soldered.

I got a surprising amount of use out of a similarly configured C720 as a general purpose portable machine.

With software that misuses /tmp, I’m more worried about burning out my SSD endurance than running out of RAM.

The screen turning off when it automatically locks is an added bonus; the priority is to be able to command the system to simultaneously lock and turn off the screen. You’re correct that the setting at zero seconds safely achieves that.

I’ve had other, more stupid uses for running commands, though I don’t think any are actively in use.

Taking actions on network reconfiguration, charge completion, and SMART failure are all things that spring to mind. It’s nice to be able to set those kinds of things in a GUI rather than putting them in /etc/something.d

What I want is not (just) that the screen turns off when the lock timer times out, but that I can push ‘lock’ or a key combination and have the system lock and the screen turn off immediately.

The new ‘when locked, turn off screen’ setting should help with this, but setting it too low will presumably make it hard to unlock.

For running backups, ‘after a period of inactivity’ could help.

It still seems like the removal of a useful feature.

I use it for turning off the screen when the screen is locked, allowing background tasks to continue.

It’s also useful to run things like backups when the system is more likely to be idle.

HDDs can fail at any time, with or without warning.

It’s not the bridge rectifier, but it’s an artifact of the operation of the switchmode power supply. Similar effects are often described as 'coil whine '.

The switching operation varies in duty cycle and frequency depending on load, and isn’t absolutely stable so oscillates a little bit. This switching supply is often in the audio range; typically between about 5kHz and 200kHz depending on design and load.

Changing current and magnetic field causes the physical components (particularly transformers/inductors) to change size and shape, and this vibration causes audible noise. At some conditions, it will resonate at an audible frequency and be loud. At other conditions, it might not resonate and/or the frequency is outside the audible range, so it’s silent.

Mains transformers do the same, causing the characteristic 50/60Hz hum. You’ll also hear the same out of cellphone chargers.

Nothing to worry about.

Secondhand stuff can be really cheap if you know where to look, but the drawbacks are usually power and noise.

No, it’s just a CPU with very good integrated graphics, sufficient to beat many cheaper GPUs.

Assuming you’re serious, no.

Most modern laptops have soldered down CPUs. Even with older or higher power models that are socketed, it’s been a few decades since they were physically interchangeable between brands, and laptops generally used different sockets to desktops. Sockets also only last a couple of generations.

You can probably buy a ThinkPad with the (lower power/performance) laptop version of this chip, though

Any modern SATA SSD will still nearly max out the bus in sequential writes, delivering sequential performance ~3x that of a spinning disk and random performance, even for the cheapest of drives, at >100x a disk.

Installing windows is not generally going to be enough to fill the drive write buffer, and even if it does, they’re still going to be comparable to spinning rust. This is a problem that affects low quality (not necessarily cheap) drives, both SATA and NVME.