Domain Mapping P3 Plugin Usage as high as .5 load (30% of plugin usage)

We have an issue where our server load is gradually "filling up". Basically the resources are being consumed very gradually and then the server's usage spikes with and we have to restart one or more resources in LAMP (usually managed services point to RAM & PHP). The last restart was a APACHE services.

So I placed a question in another support forum area and someone suggested I run the P3 plugin and cross reference it with some load tools.

The only thing standing out at me as potentially odd is domain mapping. It as much as .5 second load and 30% of total plugin chart.

I am curious if this is usual for this plugin to take that much room? It seems to be running a little higher with a-record mapping rather than NS (maybe its a coincidence). I guess is if this plugin is not performing correctly it could possibly be bottlenecking resources in trying to resolve things?

I disabled logged in users are logged into all sites option thinking maybe that will help decrease the server load some.

Any thoughts?