Working set & trimming
Which pages stay resident for a process and how Windows reclaims memory under pressure.
Related labs
Hands-on exercises for this area — in the browser or on a Windows machine.
View all labsGuided paths in this branch
Follow a short sequence step by step. Each path links to the first topic; use Read next on each page to continue.
Memory deep dive
VADs, pools, paging, working sets, and how the cache uses RAM.
Step 4 of 6 in this path
Official Microsoft docs
Closest official references related to this topic on Microsoft Learn.
Why it matters
Working set policy explains why processes get slower under memory pressure even before hard paging dominates.
Mental model
Each process has a working set of resident pages. Under pressure, Windows trims working sets to free frames for others.
How it works
- 1Frequently used pages tend to stay in the process working set.
- 2Memory pressure triggers working set trimming and broader reclaim.
- 3Superfetch and cache manager interact with which file pages stay hot in RAM.
Key terms
- Working set
- Pages currently resident for a process.
- Trim
- Removing pages from a working set to free physical memory.
A game stuttering when many apps are open
Other processes' working sets and the file cache can consume RAM, forcing trims and faults in your foreground app.
Common misconception
Task Manager 'Memory' for a process is not the full story; commit, working set, and private bytes measure different things.
You should read next
Ranked from your current topic, related links, branch depth, and any active guided path.
expert
Pool & heap
Kernel pool tags and user-mode heaps as different allocation worlds.
Next step in your guided path
intermediate
Paging & page faults
How Windows brings pages in from disk and when the page file is used.
Related topic
expert
Cache Manager
How Windows speeds file access by coordinating cached file data with memory.
Related topic