The answer depends on your issue.
Flog is slow the first time it runs for a repo
The first time Flog runs for a repo, it runs git commit-graph write.
This ultimately makes it run faster.
Disable this feature:
let g:flog_write_commit_graph = 0
Set args (defaults shown):
let g:flog_write_commit_graph_args = '--reachable --progress'
Flog gets slower over time for repos
The commit graph will eventually become out of date.
You can update it by running:
git commit-graph write --reachable --progress
Flog takes a long time to load for many commits
By default, Flog will shows 5,000 commits.
Launch with less commits:
:Flog -max-count=2000
Launch with less commits by default:
let g:flog_permanent_default_opts = { 'max_count': 2000 }
Flog takes a long time to load for complex git branch graphs
Toggle the graph with gx or launch with :Flog -no-graph.
Other issues
Please post an issue or discussion if you run into any other speed problems.
gv.vim is an ultra-light branch viewer.
gitv is a fully featured branch viewer.
Flog is faster than gitv. Flog is slower than gv.vim, but in many cases only marginally.
gv.vim and gitv rely on the output of git log --graph.
Flog draws the git branch graph itself.
This allows for branch highlighting and beautiful git branch graphs.
Flog is more customizable and flexible than gitv. gv.vim does not have any customization or flexibility by design.
Flog has features which have no equivalent in either of the other branch viewers. This includes commit marks, some navigation mappings, and contextually aware command completion.
See :help flog for all commands and options.
See examples for detailed walkthroughs.
Please start a discussion if you have any questions or post an issue if you run into any bugs.