Cache Manager
How Windows speeds file access by coordinating cached file data with memory.
What you should already know
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Storage path
Volumes, NTFS, cache, and reparse points.
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Official Microsoft docs
Closest official references related to this topic on Microsoft Learn.
Why it matters
Many performance questions in Windows come down to caching behavior rather than raw disk speed.
Mental model
The Cache Manager is the bridge between file I/O and the Memory Manager's page-based world.
How it works
- 1It maps file data into cached views.
- 2It reuses memory-backed pages to satisfy reads and defer some writes.
- 3It coordinates with file systems and the Memory Manager to preserve coherency.
Key terms
- Mapped view
- A memory-backed representation of file content used for fast access.
- Lazy writer
- A mechanism that flushes cached file data back to disk asynchronously.
Reading the same file twice
The second read may come from cached pages rather than from the storage device again.
Common misconception
Cached I/O and memory-mapped I/O are related concepts, but not identical from a programming or internals perspective.
You should read next
Ranked from your current topic, related links, branch depth, and any active guided path.
beginner
Memory management
Virtual address spaces, paging, working sets, and how Windows tracks memory.
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intermediate
File systems
NTFS and friends translating raw storage into directories, files, and metadata.
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intermediate
VAD tree
How Windows tracks ranges of virtual memory for a process.
Part of a guided learning path