Huge Midi latency with Windows

Buma's icon

Hi,
I've built a kind of "patch generator" for Prophet 12. It sends hundreds of NRPN messages to the synth via USB each time the process is triggered.
I'm a Mac user, so I've built on Mac and the standalone works perfectly fine. Flawless. But on Windows, both the standalone and the original patch are almost unusable. The concept of the patch is simple, 99 sets of parameters are generated and are stored in a Pattrstorage and on Mac, I can switch from one to another without any latency.

On Windows, it takes two or more seconds to switch between slots and Max freezes while the set of new parameters is being sent to the synth.

Is this common to Windows ? I've tried with Win 7 on Parallels Desktop and Win10 on Bootcamp.

Thanks

Buma's icon

I think I understand that "Midiout" is the issue. The amount of messages it receives seems to block / freeze Max until all the messages are sent. I was thinking that Pattrstorage was the problem, but disconnecting Midiout and I can switch presets without any problem. Of course, disconnecting Midiout is not the solution.