CPU Performance meter

I would think that depends on how much RAM you have. Audio clips and virtual instruments all take a certain amount of RAM to load. If your's says 50%, when you have 16 gigs, adding another 16 gigs should make it drop to 25%. I try to see where it's at when I first load a blank project, and not go over 60%. Of course, you'll get different results for different systems, amounts of RAM, and CPU speed, dedicated math co-processor, etc. It's not something you can really nail down. If your system is running fine at a given %, just roll with it.

The CPU meter is really just an early-warning indicator. There is no specific percentage where things start falling apart. I've had projects running at over 80% that played just fine. Technically, anything under 100% means the CPU has enough time to process data and keep the buffers filled. But if you have issues with background processes periodically jumping in and monopolizing the CPU, then you could experience dropouts even at very low percentages. 

I'm always more concerned with what an audio project SOUNDS like than with what some visual meter LOOKS like.

What about dropouts because some other process interrupts what you're doing but your CPU usage is still pretty low?

bdickens
What about dropouts because some other process interrupts what you're doing but your CPU usage is still pretty low?

When I was having a great deal of dropouts I couldn't work on any track when that meter would go about 38%
Since I've changed a few things and I'm able to go much higher now it had made me wonder since this is the first time rebuilt my own pc.
 
There are many factors that can cause dropouts and when you know your system you can tell one is coming with that meter.

Make sure you manually set your computer up for high performance mode.
 With Windows 10, don't click on the settings gear, you will need type in "Control Panel" in the Cortana search box and that will open the legacy control panel, then click on "Power Options" and make sure "High Performance" mode is selected.
 This will insure the DAW is given high priority over any and all background operations.
 
 
An AMD FX 8350 can take a heck of lot more pressure than 63% on any given core(s) and still run cool & quiet. I've seen the meters for cores peg into the red for a split second (until turbo boost kicked in) and SONAR didn't even sputter or drop a beat.
I ran and FX 8350 in my system for over 5 years.. Upgrading to the FX 8370 was so slight it was barely noticeable under "bench test" scrutiny. Under real life noticeable performance upgrade, it wasn't even humanly possible to tell the difference, i.e., it was a waste of money.
 Truth be told I wasn't all that impressed with the extra speed I gained going from the FX 8320 to the FX 8350 either as far as usable brute horsepower and system stability is concerned there is no real intrinsic difference.
 
 Also, make sure your system is also set to "High Performance" in the "AMD Overdrive" control panel, and that your Memory is set to the correct speed and running in "Duel Mode".
You most likely have DDR3 PC 1866 @933 m/Hz installed, don't ever assume that your BIOS automatically selected PC1833. More often than not particularly on older AMD systems (5 years and down) the BIOS defaults at PC 1333 @600 m/Hz or PC 1600 (?)m/Hz.
By manually insuring and correcting memory speed and timing insures best possible over all system performance,  audio and sampler performance, dropouts, etc. and such.
 And on the same token, do not try to overclock PC1333 or PC1600 to PC1833! Most likely result could be boot failure, but if it does boot you shall surely experience stability problems.
 Not that memory has anything, or little to do with CPU stress, I've also found, after splitting up/removing 16 gigs of 32 gigs of memory for a new computer build, I didn't notice any difference in DAW performance as my system running SONAR or CbB never ever came close to using 16 gigs of memory, even running several instances of high quality samplers like Dimension Pro, Rapture Pro, Addictive Drums v1 and v2 all at the same time.
 I've found the CPU meter infinitely less distracting running SONAR/Cakewalk by Bandlab with CPU load balancing engaged. My FX 8370 always stays under 40% peaks even in my most CPU intensive projects, 40 -50 tracks dozens of audio plugins running with a couple of VSTi and DXi instruments actively running, and several more, once I get what I want with the "recording/sequencing" sessions and I am happy with the sound and performances, all tracks eventually get frozen to audio.
 And that's where the project's "mixing" sessions begin, and maybe, if need be, I shall apply dozens more plugins to smooth, polish, and schmooze the project for "Mastering" sessions.
 
 I can't actually say that CPU load balancing makes either run better, it's just visually less distracting.

 Easiest way to tell how hard a plugin hits your CPU is simply to toggle it on and off and watch your CPU meter. Adding another meter just adds to CPU usage
 CPU usage info is typically contained in the plugin's documentation, and or a quick Google search. Knowing what each FX plugin is designed to do, how it does it, and [typically] where to put it is more than half the battle.
 
These lines blur in modern DAWs.
 Plugins designed for being "inserted" into the front of a channel are typically easy on the CPU. With SONAR and CbB, these are already included and "inserted" within the built into a very flexable ProChannel. A selection of Compressors ranging from Opto, FET, and tube, and add on the killa CA2A, all compression needs are fully covered, 4 different graphic EQ types, Tube saturation, and 3 different console emulation preamp modules, and each can be moved to changed to the desired place in the signal path on the strip.
 
Plugins designed for special FX like delay, flange, chorus, reverb, will hit the CPU hard to harder are typically placed in the channel's FX bin, and if you want to use any of these heavier hitting power hungry Plugins across multiple channels, you can save a lot of CPU power by running one instance of the FX plugin on an Auxiliary Buss and blend the channels from an Aux. Send.
 Or, for using any heavy CPU hitting plugin on one channel with custom tweaks, freeze the channel immediately after working on it. Believe me, you don't want to forget about it and have too many heavy hitting plugins running on too many channels, NO DAW or CPU can handle that!
 
Very high quality "Buss" Plugins and mastering bundles designed to be placed on the master buss and or used for well, MASTERING  are seriously HARD on CPU's.
 Yes you can of course use them on tracks, and these are the plugins you definitely and absolutely want to freeze the tracks ASAP.
 
Also take note that YOU CAN'T FREEZE BUSSES! All plugins running in the buss section stay running and hot
Stack too many of these heavy hitting CPU hungry Buss and mastering plugins on top of each other in the master FX bin before the final channel tweaking mixing is done.
 Running CPU hungry mastering plugins and mastering suites like Ozone on the master buss(es) before finishing recording tracks and MIDI sequencing and mixing is finished is the most common novice mistake and causes the most high latency issues and stress on the CPU.
 If you absolutely have to add another track or tweak any channels in the mix, simply shut off the FX bin on the master buss(es) that your master plugins are assigned to!
You don't need them running until you get your channel and track mix down and project right and tight.
 They use up so much CPU power they are the last processing you need to run and tweak to perfection before exporting.
 
 I've always had the habit of freezing all tracks that I'm not actively working on. I do this in practice not as much to save CPU cycles, but to make collaboration go smoother. Most artists I collaborate with don't have computer workstations nearly as powerful as my main studio machine, nor do they have the same DAW, audio plugins, and instruments.
 
 
Projects that playback flawlessly on my main powerhouse workstation would send my i7 laptop into something like an epileptic shock upon launch, and freeze up both Windows and Splat and may require holding the power button down for a Kamikaze shutdown. 
 
Freezing tracks also adds another level of security to avoid accidentally changing plugin parameters on a track or channels I'm not focused or working on. VERY easy to do with a Behringer X Touch where simply touching a fader selects a different track, or Mackie DAW controllers, and it's almost certain to happen by letting someone else put their hands on your DAW controller to try it out or tweak the mix.
 
 Leaving plugins running that you aren't actively working with is simply a waste of CPU power and even electricity by making your computer to work harder than it has to.
 The harder your computer works the hotter the CPU gets, and the hotter the CPU gets the less efficient and stable it gets, and while all AMD FX CPU's and many Intel I series can be set to shut down the system well before it becomes unstable or thermal meltdown occurs, can yours? Do you even know what the thermal threshold is?
 It's kind of like what your electric meter and fuse box does when you leave all the lights TV's, stereos, AC, and appliances running in every room of the house. 
Than you plug in one more thing and get angry when you blow a fuse. 
 
 Crashing Windows or any DAW itself by pushing your system over the edge in the middle of a work session is the best way to corrupt and or completely destroy an entire music project.
 
Common sense should tell all of us that if you are using a high powered boutique channel strip like the Shepps Omni Channel by Waves or an Eventide UltraChannel channel strip it would be a great idea to shut down the Cakewalk Channel strip. I have all  3 of these, and they are all excellent each for their own reasons, Cakewalk being by far the most CPU friendly.
 And while it's more then OK to use an EQ from one, a compressor from another, running all FX at once on multiple channel strips at once can not only double or triple the length of your signal path, degrading sound quality, it puts unnecessary strain on your computer resources. 
 
 ALL plugins designed with multiple FX modules built in (such as iZotope's Ozone), linear phase EQ's, multiband compressors, should typically only to be used on the output busses and or for mastering, and plugins such as, convolution reverbs should be assigned to run on their own buss channel and fed from multiple channel aux. sends, not separate instances on each channel's FX bin, these are ALL CPU hogs, and any plugins that require high CPU usage will show up the CPU meter in SONAR or CbB.