Benchmarks are important sometimes..
We spent 2022 moving a big SQL data warehouse into Azure and onto some of their beefier VM options.
For the next 6 months we struggled with performance. Data cube analysis that would take us 5-6 hours on our previous on-prem servers was now taking double that.
MS had helped us spec the cloudy VMs - we provided our on-prem specs and they provisioned us with the VMs that would supposedly outperform our older system.
Not even close. Our SQL DBAs spent days/weeks trying to tune the system but we just couldn't get anywhere near our old system. We even bumped the cloud VMs up a couple more performance tiers (which completely wiped out the planned budget for the system) but still had issues.
Back and forth we went with MS support until they eventually said that the setup you was running as optimally as it ever would.
So, I had to rebuild the system on-prem again and we migrated back (what fun that was).
During the switch back we had a couple of days downtime.
DBAs and I took the opportunity to absolutely smoke both systems with some benchmarking tools. The on-prem kit was so much better it was a joke. And we're not talking high-end kit here. Midrange hybrid Nimbles as storage layer, with good, but not amazing Aruba switches and a well oiled but nothing special VMware layer running the VMs.
The main weakness that we spotted on the benchmarking for the cloud stuff was disk IO, it just couldn't get anywhere close to the on-prem Nimbles.