Mar 2026 from swap subsystem engineer: Debunking zswap and zram myths
tl;dr: If in doubt, prefer to use zswap. Only use zram if you have a highly specific reason to.
Although
It only really makes sense for extremely memory-constrained embedded systems, diskless setups, or cases with specific security requirements around keeping private data off persistent storage.
…which sort of does match our situation.
But I tested this on my previous X10 II (currently on III with stock config), and concluded it’s an exercise in futility, see Low memory, apps crashing - change zram settings or add swapfile? [4.x] - #57 by lkraav for the whole story.
(AFAICT this whole 
is a duplicate “re-inventing the bicycle” work of 
but whatever.)
but running more than 4-5 applications, especially if some are Android applications, is very slow.
Yep, exactly. As memory stress increases, you will run into thrashing traps that will completely stop UI from responding to anything, for potentially several minutes at a time.
Jolla 2 with 12 GB RAM is the only real workaround for those needing to daily-drive SFOS with AAS apps at a professional clip.
On X10 III (6 GB) I still take care to manually close apps here and there to try avoid running into swap lag. Browser memory use is the worst, you literally cannot have it running in the background (auto-kill is often too late), so I close it manually after every browse session. Fortunately launch is fairly quick for this to work, but it’s still an annoying papercut.
As of SFOS 5.0, I don’t think Jolla has succeeded in aligning SFOS low-memory killer with AAS’ very well. Or maybe they have to the max available, but it just still doesn’t work out. Otherwise I think I wouldn’t feel like manually closing apps is often working out better than simply letting lmk take care of it.