Would recommend adding the specific SSD model and also adding some fio benchmarks to show the real limits of the ssd.

SSDs can be connected to a machine through raid cards or some enclosures etc. etc. And all of this makes massive differences compared to a proper on-board PCIe connection.

Also obviously SSDs have very vastly different performance characteristics.

For example an ssd might look very good at writes until you keep writing for more than some amount without any breaks, and then it becomes super slow.

Good point, I should have included that (the linked pgsql-hackers thread have some of this information, at least).

I've observed exactly this behavior on a wide range of hardware / environments, it's not very specific to particular SSDs models (at least not for reads, which is what the blog post was measuring). That's why I showed results from three very different systems.

Some information for the two physical machines:

1) ryzen: Ryzen 9 9900X, RAID0 with 4x Samsung 990 PRO 1TB (in Asus Hyper M.2 Gen5 card)

2) xeon: E5-2699v4, WD Ultrastar DC SN640 960GB (U.3)

I don't know what exactly is backing the SSD storage on the Azure instance.