View Full Version : AU vs VST?

10-09-2007, 12:45 AM
I am using Ableton Live 6 on a PPC G4 1.52ghz with 1.25gb of RAM.

I realize that I have duplicates of several plugins across multiple formats. In some cases I have AU, VST, *and* RTAS. I hope to upgrade my machine soon to a Mac Pro and work between Live and the new Logic Pro Studio...

but I'm wondering if there are any rules of thumb between AU and VST plugins while I'm just working in Live on a PPC. Does one format use more CPU (i'm starving for processing power right now)? Is one more stable?

Basically, right now I'm making uneducated guesses about whether to run my plugins as AU or VST, and I'd prefer to know if my choices are effecting either my ability to process or the quality of the final product...

10-09-2007, 11:21 AM
I really don't know if one is better than the other. I know I can't use VST in Logic Express, and I know many plugs that were VST only in years past have been converted to AUs. Aren't AUs Apple's own format? If so, it might seem they'd work better on a Mac and DAW that accepts them, but that is pure speculation.

10-09-2007, 11:27 AM
AU is OXS's native system, it's built right in, so probably more efficient.

10-09-2007, 11:58 AM
That's what I was thinking.

10-09-2007, 03:24 PM
In essence, all plug-in formats basically do the same things, so none are inherently better or worse than the other. The truth is, the reason for the Audio Units format was political, more than anything else:

Steinberg, the developer of the VST format, is extremely helpful and offers complete documentation for developers on how to build VST plug-ins, but they never offered any host documentation. In other words, each application such as Live, that supports VST plug-ins, would basically have to reverse-engineer the format to determine how to host plug-ins. Steinberg did this to give their own host applications the advantage, and true to form, no other VST host offers as compatible or seamless a VST plug-in experience as Steinberg's own applications.

So Apple developed the Audio Units format in order to develop a truly, completely "open platform." There are public, posted CoreAudio documents for both plug-in and host development. Don't confuse "open platform" with "open source"—open source means anyone can add to the code, but Audio Units are a completely Apple-owned format. However, Apple isn't keeping the hosting documentation secret, to give Logic an advantage. It's available for everyone.

So I would say, plug-in for plug-in, you probably won't see too much difference in whatever format you use, but I would not be surprised if as time goes on, Audio Units become better supported, as more hosts support AU-only and more developers stick to AU-Mac and VST-Windows to streamline their development time.


10-09-2007, 04:47 PM
Extremely helpful, thank you.