While working in Visual Studio today I noticed a message appear at the top my idea. The message stated the following:
Speed up your git experience in Visual Studio by enabling the git commit graph algorithm.
No idea what that exactly means but that sounds promising… so let’s find out
Why this commit graph algorithm?
Git repositories can become sluggish as they grow in size and complexity. If you've ever waited impatiently for git log to load or noticed that branch operations take longer than they should, you're not alone. Recently, Git introduced a powerful feature that can dramatically improve performance: the commit graph algorithm.
The commit graph is a data structure that Git uses to store precomputed information about your repository's commit history. Instead of traversing the entire commit tree every time you run commands like git log, git merge-base, or git show-branch, Git can use this precomputed graph to answer queries much faster.
Think of it as an index for your commit history—similar to how a database index speeds up queries by avoiding full table scans.
The commit graph algorithm precomputes and stores several key pieces of information:
- Generation numbers: How far each commit is from the root commits
- Commit dates: Timestamp information for faster chronological queries
- Tree and parent hashes: Direct access to commit metadata
- Reachability bloom filters: Probabilistic data structures for quick ancestor checks
This precomputed data allows Git to:
- Skip unnecessary commit traversals
- Use mathematical shortcuts for common queries
- Provide O(1) or O(log n) performance for operations that previously required O(n) time
Enabling the Commit Graph
Visual Studio will try to predict when enabling the commit graph could enhance performance. In that case the notification I mentioned in the intro is shown and you only need to click on enable.
You can also manually enable the commit-graph by going to Git > Settings > Enable commit graph for better Git performance.
Remark: When the commit graph is enabled, it can take several seconds up to a couple of minutes depending on the size of your repository before the commit graph is generated. So be patient!
As this is a git feature not specifically linked to Visual Studio, you can also activate this directly at the git level:
- First, configure Git to automatically maintain the commit graph:
git config core.commitGraph true
- This tells Git to use the commit graph for read operations when available.
- To keep the commit graph up-to-date automatically:
git config gc.writeCommitGraph true
- This ensures the commit graph gets updated during garbage collection operations.
- As a last step for existing repositories, you'll need to generate the commit graph manually:
git commit-graph write --reachable
Remark: Starting from Git version 2.24.0, core.commitGraph and gc.writeCommitGraph are on by default, so you don’t need to set the config manually.