Airwindows VST Performance

Unless something has changed in a very short time Airwindows are not optimized well at all for some AMD CPU’s. Not saying they’re not great DSP, indeed they are but the Linux binaries from the website have performed pretty badly for me on a Threadripper system in the past… just worth mentioning…

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Oh what really? I have an AMD CPU and find Airwindows VSTs to be incredibly CPU efficient, moreso than any other plugs save ACMT / Renoise stock / etc.

My laptop is 10 years old though, perhaps that has something to do with it…?

That issue has been resolved, Chris did major changes on all plugins last year in that regard. At least on my AMD those performance problems have disappeared completely I’m happy to say.


Great news!! Glad to hear it!

I’ve just split this topic from VST 3 multi-bus support into a dedicated topic, since it is unrelated to multi-out VST3.

A large performance penalty was introduced by the random number generator which is used for dithering in almost all Airwindows VSTs (rand() realtime safety on macOS and Linux · Issue #35 · airwindows/airwindows · GitHub).

This also explains why it performed significantly worse on AMD CPUs [1].

This has been mostly resolved in recent versions, although the current Linux VST code still uses rand() which is not realtime safe, and still performs a bit worse on AMD.


On an Intel […] processors RDRAND takes up to 117 clock cycles.
On an AMD Ryzen CPU, each of the instructions takes […] around 2500 clock cycles for a 64-bit operand.



Thanks for splitting the thread and for all the information. As mentioned, I’ve only seen amazing performance with Chris’ plugins thus all this was news to me.

Was it just the dithering plugins that were impscted or all Linux VSTs?

Dr. Glen, off-topic… what’s the best forum for asking questions regarding all things AVLinux? I see there is a subreddit … I just don’t want to clog up this space any more than it already is, and I’m not trying to yank your chain :slight_smile: Merci!

Hi, Lol, I wasn’t aware of the reddit…

The best places are: MX Respins - MX Linux Forum
or here: Linux Distributions & Other Software - LinuxMusicians

I had a forum of my own years ago but my schedule is too sporadic to be available consistently on a daily basis unfortunately.

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