My impression is that zswap will be the universally preferred option for compressed swap, but right now it doesn't work without disk swap behind it?
dlcarrier 2 days ago [-]
The architecture of zswap does make more sense, because you might as well combine the low speed and latency of compression with the same from writing to storage.
ChocolateGod 2 days ago [-]
You only want to use zram if you've got no swap device (e.g. a raspberry pi).
If you do, you'll want zswap instead.
iberator 3 days ago [-]
I remember that back in around 2007 i was able to somehow mount a graphical card (ati similar to geforce2?) memory directly in Linux, and put my swap file there :); Great times. Slackware 8.1 i think.
as for zram: somehow i dislike it. Nowdays ram is plenty and if not: better to have fast OOM than chug of death with swap.
I also remember running NetBSD 1.3.1 and Slackware 3 on 386SZ 26MHZ with 2 mb of ram (nowadays hard limit is 4mb to boot due the large memory pages on x86 afik)
Neywiny 2 days ago [-]
Much agreed. Early OOM is so much better for me than swap. I have 128G on my work laptop, 96 on my personal desktop. If it doesn't fit in that, it probably means I'd need a terabyte or infinite amount of swap and that's just nonsense.
sidewndr46 2 days ago [-]
This reminds me of a question I answered on StackOverflow a long time ago. I pointed out the original question was asking the computer to allocate no less than 128 gigabytes of RAM. The poster refused to accept the answer because I "didn't solve the problem, only explained why the code did not work"
Neywiny 2 days ago [-]
I mean I would indeed consider that a comment on the question rather than an answer. Unless the question was "why doesn't the work with less than 128GB of RAM?"
rcxdude 2 days ago [-]
What's old is new again: I remember various hacks like this being popular in early android ROMs because the first android phones really didn't have enough RAM to support the OS well.
phh 1 days ago [-]
Well, you stopped hearing about it, not because it stopped being used, but because its support became mainstream for a very long time. Google strongly recommends using zram on all devices, even on devices with a lot of RAM since like Android 10?
cromka 2 days ago [-]
Asahi devs initially enabled ZRAM by default and then disabled it, now recommending against it, quoting instabilities and random weirdness.
esperent 3 days ago [-]
I've heard ZRAM mentioned before and I've just spent 5 minutes reading articles on it... Which is about the maximum I have time for these days when it comes to esoteric linux internals.
What's the downside? Does it use much CPU?
If I have enough RAM already, should I still enable it?
One article says it can be mapped to /tmp to reduce i/o. Is that a good idea?
This article is light on all of these kind of details.
BenjiWiebe 2 days ago [-]
'Swapping' to ZRAM is far less painful than actual disk-backed swap. Sometimes I start wondering why the computer is a bit sluggish, and find that I've got several GB in ZRAM.
https://www.kernel.org/doc/html/latest/admin-guide/mm/zswap....
Oh right, definitely. Chrisdown wrote an article comparing the two:
https://chrisdown.name/2026/03/24/zswap-vs-zram-when-to-use-...
Zswap is supposed to degrade more gracefully.
There's even some HN comments on it:
https://news.ycombinator.com/item?id=47500746
If you do, you'll want zswap instead.
as for zram: somehow i dislike it. Nowdays ram is plenty and if not: better to have fast OOM than chug of death with swap.
I also remember running NetBSD 1.3.1 and Slackware 3 on 386SZ 26MHZ with 2 mb of ram (nowadays hard limit is 4mb to boot due the large memory pages on x86 afik)
What's the downside? Does it use much CPU?
If I have enough RAM already, should I still enable it?
One article says it can be mapped to /tmp to reduce i/o. Is that a good idea?
This article is light on all of these kind of details.