I've been having an interesting problem for a while in CM 10.2, and now still in CM11 (M3 release)..
Occasionally, I notice that the CPU seems to get 'stuck' at 384 Mhz. It took me a while to figure this out, the symptom is that the entire phone/interface gets sluggish, and if I am streaming audio over bluetooth, I get audio dropouts. I eventually figured out that what happens is the CPU is sitting at 384 Mhz, despite being at 99% or 100% cpu usage. This is most common when I am using the phone for navigation, and sometimes streaming bluetooth audio at the same time using PowerAMP.
I tried resolving it by using a tasker rule to change the minimum CPU speed when I put it in my car dock... but that doesn't seem to have helped, if I go into performance options when it is lagging, I see the current CPU speed as 384 Mhz, even if the minimum CPU speed is showing as higher than that.
I am running CM11-20140210-SNAPSHOT-M3-d2att, with UCUEMJB bootloaders.
Has anyone else seen this type of behavior? Am I outdated on bootloaders?