if anyone's curious about DPC latency in a virtual machine, here ya go



16 cores, 48GB ram, PCIe passthrough of two NVME SSDs and PCIe passthrough of RME HDSPe AIO interface

TLDR: fck no

 

Microsoft = lags. In any shape and form.

 

Been using Reaper for years with Reastream, Reasend, Reroute with multiple instances and different reapers running on different machines ( slave machines for VST's)

Have you tried using Reastream on Reaper in the master bus?

 

Using the Microsoft USB drivers rather than a chipset driver? That's almost certainly going to result in awful USB performance, which if your audio interface is USB, is going to be a bad time. Install your chipset driver.

edit: never mind, missed that it was on a VM, but the logic holds the same, if it's virtualbox there should be USB drivers in the enhancement pack I think.

 

Anything "real time" is hard on a virtual machines sadly.
They can handle charge, but not low latency.
Even LAN sharing plugins (like Audiogridder) may give you better results... a pity.

It is the same with Android VS iOS : both can handle charge BUT Android latency s*cks since day one, because kernel can't handle audio low latency. And there is nothing to do, because it is at kernel level (not on user side).

As a side note : you MAY compete with Audiogridder by using USB pass through.
VirtualBox support USB passthrough audio devices (with the Extension Pack installed).
https://duino4projects.com/virtualbox-usb-passthrough-guide/

Without USB PT, Audiogridder like (reaper Rea ...) get less latency.

 

A virtual machine is basically an operating system running inside an operating system. If you think about that, no matter how grunty any person's system is, the response times for anything will all have some form of lag, however minor(unnoticeable), or extreme(very noticeable).

 

There’s always some extra latency when running an audio plugin inside a VM, no matter which OS is loaded. The same applies to running plugins through Crossover, Wine, or Mac’s Rosetta translation — all of these add a small amount of processing delay. A faster system can reduce this to the point where it’s barely noticeable, but it’s never zero. Because this latency happens between two operating systems, most DAWs can’t detect it and won’t apply plugin delay compensation for it. Sometimes you can improve results by switching which OS is the host and which runs in the VM, but there’s always some overhead.