PT and CPU usage

[DonaldM]

Maybe one of you computer savvy folks can help me understand this. I do not understand the CPU meter in the System Window in PT. One of my VI's, Synapse Audio's Dune 2, is a bit of resource hog. I wanted to see how much. So I opened an empty session, instantiated one instance of Dune 2, and played 1 patch. I turned the multithreading on in Dune 2. Just playing the patch live via my midi keyboard, and the CPU meter in PT pegs out in red at 100% falling back to around 70% depending on how many notes I'm playing. Changing the Disk playback doesn't seem to make too big a difference either.

But, and here's the confusing part, if I look at the CPU meter on my Windows usage screen (not the PT one), it says that PT alone with nothing going on uses about 3% CPU, but once I start playing the patch in Dune 2, it jumps to about 25-30% CPU usage. But the PT meter goes 70-100%. What accounts for the difference? What exactly is the PT meter measuring? I'm just trying to understand it.

[LightWing]

Great question Donald. I've basically given up on trying to figure that out and chalked it up to a "Mystery Of Pro Tools Science".

[chrisdee]

I too have Dune 2. I'm on Windows 7 with PT 12.8.

I've noticed that some of the patches can be really resource hungry (like some pads) but most are pretty CPU friendly.

Have you tried many different patches?
Are you on Windows 7 or 10?

[junkgear]

Originally Posted by DonaldM

Maybe one of you computer savvy folks can help me understand this. I do not understand the CPU meter in the System Window in PT. One of my VI's, Synapse Audio's Dune 2, is a bit of resource hog. I wanted to see how much. So I opened an empty session, instantiated one instance of Dune 2, and played 1 patch. I turned the multithreading on in Dune 2. Just playing the patch live via my midi keyboard, and the CPU meter in PT pegs out in red at 100% falling back to around 70% depending on how many notes I'm playing. Changing the Disk playback doesn't seem to make too big a difference either.

But, and here's the confusing part, if I look at the CPU meter on my Windows usage screen (not the PT one), it says that PT alone with nothing going on uses about 3% CPU, but once I start playing the patch in Dune 2, it jumps to about 25-30% CPU usage. But the PT meter goes 70-100%. What accounts for the difference? What exactly is the PT meter measuring? I'm just trying to understand it.

I have no idea how it's calculated or how it actually comes up with the percentage, but from what I understand, the CPU meter in PT does not measure how much of the CPU is being used, like the one in Windows Task Manager. Rather it is a indication of CPU load for your current session. So, if you have one CPU intensive plug-in, it could demand 90% of the CPU resources, which indicates that there isn't much left and you will probably hit errors if you add more. I'm not sure if the plug-in reports a needed CPU load, similar to how it reports latency.....

Would be nice if an Avid rep could chime in....

[Wizzoboy]

According to the reference manual,

CPU Meters
The CPU Total meter displays session performance
for Elastic Audio processing, Clip Gain processing,
and Native plug-in and mixer processing.
The individual CPU meters provide a general indication
of how much Pro Tools is using each of the
processors in your computer.

[DonaldM]

Originally Posted by chrisdee

I too have Dune 2. I'm on Windows 7 with PT 12.8.

I've noticed that some of the patches can be really resource hungry (like some pads) but most are pretty CPU friendly.

Have you tried many different patches?
Are you on Windows 7 or 10?

I'm on Win-10, and yes, different patches use different levels of resources, but, even so, over-all, Dune 2 is a bit of a resource hog. So is Xfer's Serum, and quite often, Omnisphere. Its the nature of the beasts!

[DonaldM]

Originally Posted by Wizzoboy

According to the reference manual,

CPU Meters
The CPU Total meter displays session performance
for Elastic Audio processing, Clip Gain processing,
and Native plug-in and mixer processing.
The individual CPU meters provide a general indication
of how much Pro Tools is using each of the
processors in your computer.

Yes, I know that's what the manual says, but it doesn't really make sense if PT is using, say, 90% of processor power, and the general Windows meter shows 27%...its a bit confusing as to what exactly the meter is telling you.

[EGS]

Make sure CPU cores are un-parked.

[amagras]

What I will never understand is why just opening PT without any session open would sometimes take half the CPU, sometimes even with red spikes (this happens one day without making any other changes)

[EGS]

"What I will never understand is ..."


Do all AVID recommended system tweaks
Post your complete system specs including a Sandra report
Ask a clear & concise question
Thoroughly read the "Help Us Help You" tab at the top of the forum page

Then...

we will help you understand.