At least I have the impression they are lagging, eg., still offering things like: z1d: Skylake (2017) https://aws.amazon.com/ec2/instance-types/z1d/ x2i: Cascade Lake (2019) and Ice lake (2021) https://aws.amazon.com/ec2/instance-types/x2i/
I have not been able to find instances powered by the 4th (Q1 2023) or 5th generation (Q4 2023) Xeons?
We solve large capacity expansion power market models that need as fast single-threaded performance as possible coupled with lots of RAM (32:1 ratio or higher ideal). One model may take 256-512 GB RAM, but not being able to use more than 4 threads effectively (interior point algorithms have very diminishing returns past this point)
Our dispatch models do not have the same RAM requirement, but you still wish to have the fastest single-threaded processors available (and then parallelize)