You’ve probably seen a line like this in a paper or grant report: We used 10,000 GPU-hours. It looks like a useful answer. There’s a number and a unit. Very official. But what does a GPU-hour actually measure? On its own, pretty much nothing. I can’t compare that number with another project until I know what counted as a GPU, whether it was a whole device or a slice, and how the authors calculated the total. ...
Is GitHub down if the website loads but GitHub Actions doesn’t work? Technically, no. A lot of GitHub is still available. You can browse, review things, and push a commit. But if your release process depends on Actions, a big piece of GitHub is absolutely down for you. The same thing happens with clusters. The login nodes might be available while storage is having problems. Most of the compute nodes might be healthy while one GPU partition is offline. The owners can truthfully say that the cluster is up, while a researcher can say that they can’t do their work. ...