Changes

# Speed. Less Firefox will be faster due to less cache pressure, less paging, and fewer/smaller GC and CC pauses. Changes that reduce memory consumption but make Firefox slower are not desirable.# Stability. Fewer Firefox will suffer fewer aborts/crashes due to virtual or physical memory exhaustion. The former is mostly a problem on 32-bit Windows builds with a 2GB or 4GB virtual memory limit, the latter is mostly a problem on mobile devices that lack swap space.# Reputation. Fewer people will complain about that Firefox being is a memory hog, and fewer people will complain that Mozilla ignores memory usage.

Reducing memory consumption directly helps with both stability and reputation. The effects on speed There are usually murkier, and the effects depend greatly on the nature of any individual reduction and the machine Firefox is running on; changes that two main ways to reduce Firefox's memory consumption but make it slower are not desirable.

There are two main facets to this. # "SlimmerSlim down" memory usage, e.g. make data structures more space-efficient data structures.# Avoiding Avoid "leaks". This loose use of the term (which is used throughout this document) includes:

#* Collection heuristic issues (e.g. GC is too infrequent in certain cases).

Leaks are generally more important, as because they are more likely to lead to horrible performance.