Max-P

To kind of visually see it, I found this thread of some guy that took oscilloscope captures of the output of their UPS and they’re all pseudo-sines: https://forums.anandtech.com/threads/so-i-bought-an-oscilloscope.2413789/

As you can see, the power isn’t very smooth at all. It’s good enough for a lot of use cases and lower end power supplies, because they just shove that into a bridge rectifier and capacitors. Higher end power supplies have tighter margins, and are also more likely to have more safety features to protect the PC so they can get into protection mode and shut off. Because bad power can mean dips in power to the system which can cause calculation errors which is very undesirable especially in on a server. It probably also messes with power factor correction circuits, which is something cheap PSUs often cheap out on but a good high quality one would have and may shut down because of it.

As you can see in those images too, it spends a significant amount of time at 0V (no power, that’s at the middle of the screen) whereas the sine waves spends an infinitely short time at 0, it goes positive and then negative immediately. All the time spent at 0, you rely on big capacitors in the PSU to hold enough charge to make it to the next burst of power. With the sine wave they’d hold just long enough (we’re going down to 12V and 5V from 120/240V input, so the amount of time normally spent at or below ±12V is actually fairly short).

It’s technically the same average power, so most devices don’t really care. It really depends on the design of the particular unit, some can deal with some really bad power inputs and manage just fine and some will get damaged over long term use. Old linear ones with an AC transformer on the input in particular can be unhappy because of magnetic field saturation and other crazy inductor shenanigans.

Pure sine UPSes are better because they’re basically the same as what comes out of the wall outlet. Line interactive ones are even better because they’re ready to take over the moment power goes out and exactly at the same spot in the sine wave so the jitter isn’t quite as bad during the transition. Double conversion is the top tier because they always run off the battery, so there’s no interruption for the connected computer at all. Losing power just means the battery isn’t being charged/kept topped off from the wall anymore so it starts discharging.

Latest (0.19.8). 0.18 is very old, over a year old, later versions dealt with a lot of scaling/performance problems.

That sounds very typical of YunoHost to have wildly outdated software

1. It seems to make a LOT of calls to other servers. Its almost constantly pinging other servers asking for updates.

The fediverse works the other way around: other instances push activities to yours. If you have a lot of subcriptions to large communities like !technology@lemmy.world it will indeed receive a lot of activities.

2. It gets de-federated almost instantly from popular instances. Which kinda sucks.

Mine’s not been defederated from anywhere, not even Beehaw

3. It uses up quite a bit of CPU compared to other federated applications.

It definitely uses a fair bit of CPU but it is ingesting a fair amount of data, but still not a ton either:

Although I do hear PieFed is a lot lighter.

4. Subscribing to instances seems to work most of the time, but sometimes it just errors out and I have to re-do it.

That settled for me after a week or so of running mine. My subscriptions always go through.

If you look at my username you’ll see I do run my own instance so I’ve gone through the process :)

I would probably just skip the Lemmy Easy Deploy and just do a regular deployment so it doesn’t mess with your existing. Getting it running with just Docker is not that much harder and you just need to point your NGINX to it. Easy Deploy kind of assumes it’s got the whole machine for itself so it’ll try to bind on the same ports as your existing NGINX, so does the official Ansible as well.

You really just need a postgres instance, the backend, pictrs, the frontend and some NGINX glue to make it work. I recommend stealing the files from the official Ansible, as there’s a few gotchas in the NGINX config as the frontend and backend share the same host and one is just layered on top.

Hasn’t cost me a penny, hurray for unmetered bandwidth