I have just upgraded my 2015 Macbook pro from MacOS 10.15.7 to 11.2.
Under 11.2 Boinc Manager 7.16.14 uses 64% of my CPU while in simple view. This is in addition to any tasks that are processing.
When in advanced view, the manager CPU drops to between 0.5 and 10%.
If I run on battery, in simple view, manager indicates that it is paused, but it still uses 64% of my CPU, even though no tasks are running.
In advanced view on battery, again it drops to between 0.5 and 10%.
If I run on simple view with a mutually exclusive app active, Boinc manager tells me that workload is suspended because an exclusive app is running. Yet it still consumes 64% of my CPU. Switch it to advanced view and this drops to between 0.5 and 10%.
This is new behaviour which did not happen under MacOS 10.15.7.
The extra CPU consumption is untenable, therefore I have discontinued BOINC on my laptop for the time being.
I look forward to a solution.