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Reminder: Enable ZRAM on your Linux system to optimize RAM usage

17 pointsby type0yesterday at 10:19 PM8 commentsview on HN

Comments

Kim_Bruningyesterday at 11:41 PM

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

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ChocolateGodtoday at 12:17 AM

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.

esperentyesterday at 11:49 PM

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.

iberatoryesterday at 11:25 PM

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)

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