*Note that the suggestions are accompanied by an open question; for users to share what other software they know could affect CPU settings.
Basically you could set specific power plans for differing usage needs. Note that existing plans can be modified entirely. I have a High Performance plan, a Power saver, a Media Playing (where you don’t pause while the laptop lid is closed), etc.
For Processor Power Management --at High Performance-- you set the Min to 100% and the Max to 100% as well, so the CPU doesn’t go to to rest (watch your T°s afterwards) this also lowers DPC risks. */1
At Power saver plan you may set Min 0% (or 10% as I do) so to lower electricity consumption and T°s.
For PCI I always go for the less restrictions and max configuration, since at audio your system needs the less latency and the best information flow you may attain.
However, particularly in the last decade CPUs have wildly varying specifications. Each architecture has brought novel protocols and ways to improve processing, power efficiency, security, memory and single/multicore handling…
Which means your personal results may vary according to your system, hence test it for yourself. For that, you may take it to extremes and then carefully measure. We are finding out that SL 7 is quite a strict test, while performance environments like Live, Djing, Recording, have always been that way.
*/1 Intel’s Turboboost is known to cause DPC spikes in audio, so it is recommended to be turned of.