Why does Phase Modulation in ZynAddSubFX hog CPU?

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In most songs, I cannot use more than two or three instruments at the same time with Phase Modulation (PM) without the CPU meter going through the roof. Why is this? Is there any realistic way to get around it? I really like some of the sounds I can make with it, I'd hate to be restricted in this way.... :(
Douglas wrote:
Mon Jun 12, 2017 12:21 am
In most songs, I cannot use more than two or three instruments at the same time with Phase Modulation (PM) without the CPU meter going through the roof. Why is this? Is there any realistic way to get around it? I really like some of the sounds I can make with it, I'd hate to be restricted in this way.... :(
So uh, dunno if this is also a cause to your problem, but anything above 10 voices using chorus additive in the AdSynth will cause some heavy lag.
Jacoby Davis wrote:
Mon Jun 12, 2017 1:00 am
Douglas wrote:
Mon Jun 12, 2017 12:21 am
In most songs, I cannot use more than two or three instruments at the same time with Phase Modulation (PM) without the CPU meter going through the roof. Why is this? Is there any realistic way to get around it? I really like some of the sounds I can make with it, I'd hate to be restricted in this way.... :(
So uh, dunno if this is also a cause to your problem, but anything above 10 voices using chorus additive in the AdSynth will cause some heavy lag.
I thought the voice maximum was eight...? Or am I misunderstanding you? Sorry, I have Asperger's Syndrome, which makes me have a math-based mind while normal people have language-based minds, so misunderstandings are quite common.... :/

But no, it is definitely the Phase Modulation that is causing it. The same instrument takes up over three times the CPU (but only while playing) with Phase Modulation than without. Am I the only one with this problem? I think this would be an issue for everybody... well, at least the people who use Phase Modulation in ZynAddSubFX.

In case it matters, I am using Debian Linux.

EDIT: Also, I'm only using up to three voices, so that is definitely not the problem. It's definitely the Phase Modulation.
I don’t think I can help you, but here are some questions:

- In the general configuration of LMMS, what is the size of the buffer (frames + latency)? Perhaps it should be adjusted?

- Is your PC optimized for audio? For example, are there several programs that work at the same time when you use LMMS (like antivirus, internet, etc.)? (you could search on the net the following keywords : optimization pc audio daw).

- Is your pc powerful enough? (What are its specifications?)