I came to this forum (and the many posts about CPU efficiency) when I searched CPU spikes in Studio One on Google. I was having horrible CPU spikes that would only show up with larger projects and it was driving me insane. This post isn't to go against the Feature Requests about CPU efficiency. I totally agree that CPU usage in Studio One is behind other DAWs - probably 2-4 times worse than Sonar in my unscientific tests. But this is more of a solution oriented post than a complaint.
Anyway, I'm running an I7 6800k with 64gb of Ram, multiple SSDs, etc. and should not be having random CPU spikes. I tried running Latency Mon, disabling all my drivers, reinstalling Studio One numerous times, killing all processes, Disabling C states and EIST in BIOS - everything I could find. Still, the spikes were killing my workflow and making it really hard to get stuff done.
I had read in a few places about disabling Turbo Boost in BIOS (and Turbo Boost Max) but had decided that there was no way I was going to sacrifice CPU power. Well, it got bad enough that I decided to try it and VOILA - for the first time ever for me in Studio One - NO CPU SPIKES!
My CPU is about 10-15% higher without Turbo Boost on but finally I have rock solid consistent numbers. If it's hovering at 35%, it will go up and down maybe 3% but that's it. Before it would spike to 100 every second or so. This should be considered a bug in it's own right because no user should have to go into BIOS and disable a CPU feature hat makes their computer run much faster but at least I have a fix that allows me to get work done.
Anyway, I know this was a super long post but this helped me so much and I figured it could help some of you out there as well - at least until the CPU issues with Studio One get ironed out.
Also, just want to say I love Studio One and if you guys can get CPU efficiency up there with the rest, and set up track templates/session import - it will be unrivaled. Thank you!