CPU usage and hyperthreading

Feb 2, 2012 at 11:11pm

CPU usage and hyperthreading


I’ve recently built a granular synth/sampler using a groove~ inside a poly~ and have noticed that the max audio status says that I’m using around 20% CPU when its running at full tilt with 16 instances. The CPU monitor in OSX however says that max is using between 70% and 115% CPU. I’m slightly worried as to the discrepancy between the two, not to mention the fact that apparently my CPU can work at 115%. I have tried using two poly~’s in tandem, each running 8 instances with the parallel setting switched on to see if this eases the processor load but to no avail. I was wondering if anyone has any advice re: the discrepancy in CPU readout or how I might achieve some effective parallel processing.

Thanks in advance


Feb 3, 2012 at 12:12am

Is parallel on in the first instance?

A few things to note:

1 – Audio status only looks at the CPU used to cacluate audio. :You may be seeing graphical stuff or something else.

2 – For Max 100% means “no CPU time left”, so that means all processors/cores maxed out. Activity monitor shows 100% for one core maxed out, so if you are running acoss 4 cores at 80% in activity monitor, you would expect to see about 20% in the max CPU monitor.

It sounds to me like everything is fine – the figures just mean something different to what you expect.


Feb 3, 2012 at 8:26am

Hey Alex,

Thanks for your response. I have parallel turned on in the inspector and in DSP setup (Max6). I have also tred tried sending parallel messages to the poly~ objects etc…

I was hoping to see some sort of vast drop in CPU usage with the parallel processing switched on but from your explanation I can sort of understand why not. Also I read recently that having a dual core processor won’t actually double your processing power rather than add around 25%. I’m not sure how true this is myself?


Feb 5, 2012 at 11:32am

I just bought Gen and now all the above is being far less CPU intensive!? Bearing in mind that I haven’t altered anything to include any Gen patches, does Gen somehow unlock some different processing capabilities for the overall MSP engine or is this a Max quirk?


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