I work in games, our repository is ~100GB (20m download) and a clean compile is 2 hours on a 16 core machine with 32GB ram (c6i.4xlarge for any Aws friends). Actually building a runnable version of the game takes two clean compiles (one editor and one client) plus an asset processing task that takes about another 2 hours clean.
Our toolchain install takes about 30 minutes (although that includes making a snapshot of the EBS volume to make an AMI out of).
That's ~7 hours for a clean build.
We have a somewhat better system than this - our base ami contains the entire toolchain, and we do an initial clone on the ami to get the bulk of the download done too. We store all the intermediates on a separate drive and we just mount it, build incrementally and unmount again. Sometimes we end up with duplicated work but overall it works pretty well. Our full builds are down from 7 hours (in theory) to about 30 minutes, including artifact deployments.
Our toolchain install takes about 30 minutes (although that includes making a snapshot of the EBS volume to make an AMI out of).
That's ~7 hours for a clean build.
We have a somewhat better system than this - our base ami contains the entire toolchain, and we do an initial clone on the ami to get the bulk of the download done too. We store all the intermediates on a separate drive and we just mount it, build incrementally and unmount again. Sometimes we end up with duplicated work but overall it works pretty well. Our full builds are down from 7 hours (in theory) to about 30 minutes, including artifact deployments.