Dear, i am using MongoDb atlas with M40 configuration.
When use M40 General, CPU is stability ~70% with abount 1300-1500 connections
but when switch to M40 SSD NVMe, CPU is up to 100% with the same traffic.
SSD => more CPU, less disk
Old HD => less CPU, more disk
We need to compare the latency of both. You gave a number but it is not clear for which. The specific number is also useless. The comparative values are important. The comparative values at different traffic load can be useful.
Are you maxed out in terms of traffic in any of the two cases?