I can stick my oar in here and say it idles at about 5%, if that on my Windows 7 PC running a Core2Duo 2.8GHz CPU.
Also, on a Intel Celeron 1.9GHz CPU (what is originally a) Dell Windows laptop running Mac OSX 10.6.7, I’m idling at about 5-10%, if that.
Therefore, if it’s happening on Macs, seems to be linked to Apple hardware rather than the OS as OSX runs it fine on my Dell laptop, even with a cruddy old 1.9GHz Intel Celeron M CPU.
I hammered on my lil Toughbook all weekend and while I did manage to get my CPU meter in the red it never clicked, popped, or dropped audio. 4 tracks + effects and anything else I could do. S4 or timecode+X1. I found that DVS definitely pushed it the most.
Toughbook CF-W8
1.2GHz Core2Duo - 4GBs RAM
Win7 Pro 64
Audio4DJ 2.0.15 drivers.
TSP2
Wifi was off and running in full screen mode.
a temporary fix that i use with TP1 when im using the internal sound card on my lappy, is to turn of the effects units when youre not using them. (from the middle, not the global section)
It’s not crashed on me, but I have had the Traktor CPU meter going nuts at times. Particularly loading several samples one after the other in quick succession.
I’ve also been telling people it’s a more sensitive meter, but I have noticed audio crackles at times and I’ve got my latency significantly higher than I had it in 1.2.7.
I had some freaky issues to start with. I transplanted my old traktor settings from TS1 and overwrote the TP2 settings.
TP2 then took ages to load, the CPU was maxed out and I had pops and clicks everywhere.
Proceeded to nuke the settings file, loaded back up, no issues since.
My PC on Win 7 idles at about 20 - 30%. Ive not had any problems with 2 timecode decks, 1 intenal, 1 sampler & all 4 effects banks. Butter.
Just to make you fellow Mac guys feel at rest. Open up Traktor (and only Traktor if you’re that worried) 4 decks, an effect on each, keylock IF you use it, (I don’t personally) then open up Activity Monitor and see for yourself. On the top area for individual programs, I have Traktor clocked in at 56%. Where as on the bottom where it shows, User, System, and Other - User shows at 33% CPU, and that’s with me having firefox open, facebook chats going off, and having a youtube video running. So yes, its a bug/new way NI just wants to show CPU usage. Oh well, long as your activity monitor says you’re in the green, you’re good. Also - inside Traktor, my bar is around 34-45% idling and with those 4 decks and FX going on. So I’m not worried about it, when I’m at home (in class right now) and I was running last night, it was around 10-15%. So, it changed, must be some weird variable. Just live your lives till they comment on it or fix it if its not performing as intended.
The User/System/Idle will always add up to 100% because that’s a percentage of your entire system.
However, any individual app can go over 100% (if you have more than one core and it’s multi threaded) because that’s a percentage of a core.
See attachement for a quick example.
Same thing happened to me, hence I’ve started fresh.
At the mo T2 isn’t ready for gigging, I’ve got my latency wound up over 3 times what I had it on 1.2.7 and I’m getting snap crackle and pop just when I’m beat juggling, add key lock to the party and that really piss’s it off!
My post was meant as an explination. I know that it adds up to 100%
So was mine, and it was the second half that was important.
Think of it as an extension of yours, not a retort to it. 
Sorry if this is a necro post, but i am also having the same issue, when im using my audio 6 theres hiccups here and there, cpu meter is always at between 30-50 with spikes that seem to be pretty random, working on optimizing my system, put the latency at the least straining it could be. currently running:
pc
amd athalon 2.1ghz
3 gb ram
was running:
intel celeron 1.6ghz
2 gb ram
seemed to actually run better on on my old laptop
could this be a bug that will be fixed in future versions of tsp2? could it be a driver issue with the audio 6?
I just recently bought an S2 and I was experiencing the same problems. I turned off the Multi-Core Processor Support in Preferences>>Audio Setup and it fixed the CPU spikes. Seems to be running fine now…don’t exactly know why though.
Hope this helped.