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.
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.
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)
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.
There's also kernel zswap, right?
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
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?
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.
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.
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.
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)
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.