Disk limit

Settings → Maximum cache size is off by default, because a cache is meant to grow. Set a ceiling — 250 MB up to 10 GB — and when the cache goes over it, the pages stored longest ago are cleared first, a few at a time in the background, until it is back under.

Oldest by written rather than read: recording a read would mean writing to disk on every cache hit, which is the one thing the fast path must never do.

Most sites never reach any of these. A thousand cached pages is usually well under 100 MB.