[dagw]

The only real advantage cloud has for science is object storage

As someone who has done a fair bit of HPC I consider the real advantage to be temporary scalability. If my 'normal' compute notes have 128 GB of RAM and all of a sudden I have job that need 300 GB or RAM, with cloud I can just change a line in a config file and run that calculation on a machine with 300 GB of RAM. Or if I have a job that will optimally run on 100s of 1-core machines with only 4 GB of RAM I can set up a cluster of such machines with in minutes.

That being said I 100% agree that if you have a normal baseline workload that should absolutely be done on in house hardware.

[SpaceMartini]

Those are fair points - I have seen truly spiky workloads like that very occasionally, but more often those spikes are a precursor to more sustained usage in a similar manner and so would quickly warrant hardware purchases.