We've got exactly the same issue on a CS215. We've got a call logged with support and I'm waiting for them to come back to us.
We can see that it started occurring immediately after upgrading from firmware 2.2.10 to 220.127.116.11. The load profile has been pretty consistent before and after and the CPU stats just stand out as an anomaly.
I'll let you know what we hear back from support.
It's probably worth mentioning that the Performance Report part of Infosight is a rollup of the weekly performance of the CPU for the system, not just for application I/O but background work such as garbage collection. Therefore, sometimes these reports can throw up "false positives" in indicating CPU usage is higher than it is.
It's worth going into the "Performance Details" part of the asset and drill into the time that the report is showing spikes of CPU usage, and see if or when they occur. Chances are there wouldn't be many CPU spikes noticed after the firmware upgrade.
Here's an example of one of my customers, who is seeing the same increase within the Performance Report:
But the deeper analysis of the Performance within the asset (a tool that support call Coral, as it correlates everything from I/O, latency, CPU/cache overprovisioning etc), not much has changed from before the firmware upgrade with average latency & I/O - it's still a very respectable average latency of 1-2ms
Having said the above, there are numerous background features in NimbleOS 2.3 for I/O blender QoS and enhanced I/O handling, which may be more taxing on systems which have less CPU such as the CS200.
Something else has just occured to me, and this is purely speculation... it seems that everyone posting in this thread is on CS2xx as well as NimbleOS 18.104.22.168. That firmware has been deprecated and 22.214.171.124 is the recommended release, with about 70 bugfixes between the releases. I'm wondering whether it's worth testing an upgrade to see if it reflects any change?
Just got off the phone with Support and he checked with the performance engineers and the increase in CPU usage is expected behaviour is expected as the new firmware packs a lot of extra features, and in the 2xx series you see a bigger increase in CPU as this CPU has a bit less power then the higher series.
The Array that we where having problems with has reached the max of it's performance and this slight increase in CPU usage probably tipped it over the top.
I will keep an eye open on the one test nimble I've upgraded yesterday and see in a few weeks how Infosight is showing it's performance.