Browser.cache.memory.capacity
Background
When a page is loaded, it can be cached so it doesn't need to be rerendered to be redisplayed. This preference controls the maximum amount of memory to use for caching decoded images and chrome (application user interface elements).
Possible values and their effects
-1
Automatically decide the maximum memory to use to cache decoded images and chrome based on the total amount of RAM. (Default in all but Thunderbird and Minimo).
| Physical RAM | Memory Cache (in KB) |
|---|---|
| 32 MB | 2048 |
| 64 MB | 4096 |
| 128 MB | 8192 |
| 256 MB | 14336 |
| 512 MB | 22528 |
| 1 GB | 32768 |
| 2 GB | 45056 |
| 4 GB | 59392 |
0
Do not cache decoded images and chrome in memory.
Any positive integer
Maximum amount of memory in KB to use to cache decoded images and chrome (1 MB = 1024 KB). Thunderbird default: 4096 KB; Minimo default: 256 KB.
Caveats
- browser.cache.memory.enable must be true for this preference to take effect.
- Lowering this value causes less memory to be used but also increases the load time of previously visited pages and dialogs. Raising it has the opposite effect.
Recommended settings
Users who are having problems and want to lower memory consumption can try adding the "browser.cache.memory.capacity" preference in about:config or via the user.js file and setting the integer value to something lower than the memory cache setting given in the above table. Note: You can view the maximum memory cache currently in effect by entering about:cache in the Location Bar. Look under "Memory cache device" at the entry for "Maximum storage size".
Users who have no problems with memory should leave the setting at -1.
First checked in
Has an effect in
- Netscape (all versions since 6.1)
- Mozilla Suite (all versions since 0.9.1)
- Phoenix (all versions)
- Firebird (all versions)
- Firefox (all versions)
- Thunderbird (all versions)
- Minimo (all versions)
- Seamonkey (all versions)
Related bugs
- Bug 85054 - Hard Drive grinds when disk cache set to zero.
- Bug 105344 - Memory cache pref should be a percentage of physical RAM
- Bug 204164 - Calculating memory cache as percentage of physical memory may not be such a good idea
- Bug 296538 - limit the memory cache to a reasonable value
