Vite build is very slow as compare to webpack build

[coure2011]

I recently converted my large project from webpack vue-cli based to vite. When building the code its very very slow.
Webpack vue-cli: ~2 mins
vite build: ~13mins

Using
vite: 2.9.12
node version 14.x

I am not sure how to start investigate whats taking too much time.

[jacekkarczmarczyk]

Here are my benchmarks of Vite vs Vue Cli

First row - Vite (2.9.x), second row - Vue Cli (5.0.x), first column - first build, second column - second build right after the first one. So while first build is faster in Vite second one is much slower, looks like Vue Cli/Webpack caches something and Vite doesn't.
Both builds are done with legacy

[coure2011]

If I disabled the @vitejs/plugin-legacy then the build time drops from ~790 secons to around ~90 seconds.
So looks like this was taking a lot of time

[dews]

I have the same experience.