[wyldfire]

It's probably a testament to the scope of the build + test that makes it four hours. If it were faster, would the scope tend to increase in order to hit more tiers/more tests?

I'd rather my commit sit in a test queue for several hours than push and cross my fingers like LLVM does it.

[centril]

With faster builds, would probably reduce the queue latency and land more PRs. We'd probably also allow more toolchains to be tested and whatnot.