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Comment by vidanay | Hacker News Reader

Ram is meant to be used. Ram should be 100% utilized

Yes, but if your application assumes that it should use 100% of my RAM, it's being antisocial. Don't assume that I don't have more important software that could be utilizing my RAM in ways more important to me.

That's what drives me up a wall whenever people use the "free RAM is wasted RAM" argument; the assumption that RAM unused by your software is unused by me.

Android found a kind of solution for this by agressively killing processes (while saving their state). This seems to be effective because developers are not motivated to help competing applications, they want to have all resources for themselves.

That's perhaps great in android, but you can't/shouldn't write code for Linux/Windows/MacOS, where such a system is not in use, and then protest "I'm not the one that sucks." Maybe those OSes should implement such a system, but until they have the "wasted RAM" argument needs to end for anything other than specialty professional software that can reasonably assume itself to be the raison d'être of that computer (e.g. video editing software, CAD, build systems for large software projects, etc.)

Windows has such a system with UWP. I think UbTouch or whatever the Ubuntu phone successor distribution is called has one too.

And I imagine most systems programmers could define an api if they wanted to.

I think this is definitely a case where apps need to be antisocial and operating systems need to peg them in. The age of cooperative multitasking is over. Let the OS decide.

Harming users to coerce OS designers is a pretty shitty plan. Sorry if that's too blunt, but that's simply the way I feel.

The operating system should be responsible for managing resources like RAM, and applications should be responsible for using the right resources. Caching video is absolutely a RAM thing, since it's expected to go away once the video is done. Caching downloads is a separate matter, since it's expected to stay once finished.

A good litmus test here is what you expect to happen if the machine reboots. For video, I think it's reasonable to lose all video cache, but I think downloads should be resumable. If it shouldn't be there on a reboot, use RAM. If it should, use disk.

There are certainly exceptions, but I think the general rule of thumb is useful.

I have 4 Gb of RAM and most of time it is utulized over 100%. Not a very pleasant experience with modern Electron apps and reactive HTML5 sites.

Spoken like someone who has truly zero understanding of how RAM usage relates to performance.

Repeat after me: high data locality reduces the amount of cache misses, which drastically reduces memory latency, and is only achievable through systematic memory usage conservativism.

You're assuming this person understands data locality, or memory latency or even memory in general.

Try running Office, Chrome and Teams on a constrained system, then say that again!

You seem to be ignoring a very important factor here, energy consumption. RAM usage has a direct effect on battery usage and battery usage is an important factor and selling point these days.

Does it? I was under the impression that all the installed RAM got refreshed all the time whether it holds useful data or not.

Surely not as bad as disk.

RAM _capacity_ has a direct effect on energy, usage not nearly much if at all.

Hardware has been around to selectively put banks into low power saving mode, but I've never heard of any commodity OS that supported anything like that. It'd require active organization of physical pages to take advantage of, if common controllers even supported it

Note that most of RAM's power consumption comes from reading and writing (a function of memory clock speed). Allocating the RAM itself is likely to meaningfully increase power draw, but accessing it will.

Are there any benchmarks around showing this? And how much extra power draw it is.

The state of bits in RAM has zero effect on energy usage. Caching things in memory allows for lower power consumption, though, by preventing duplication of effort by the CPU.

Edit: Originally said "zero effect on memory usage", which makes very little sense!

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