Hi all. I think this is a topic which is specific to Vienna Instruments. I have tried loading multiple (16+) instances of other virtual instruments and I do not have the problems that I have with Vienna.

Ok, I'll try and keep this simple. If I create a Logic arrangement with around 16 or more stereo instances of Vienna Instruments, with my buffer set to 64, Logic will distribute the load evenly across the 8 cores of my MacPro during playback. But this is only the case if I do not have one of my Vienna Instruments tracks selected to play / perform / record. During playback, if I click on any of the channels which have a Vienna Instrument on to compose or record a new section, one of the 8 cores (which is always no.8 BTW) will shoot up into the red causing glitches, distortion, and error messages. The other 7 cores are at about 5 - 10%

This happens even if there is no reverb plugins open at all. My conclusion - when composing, 16 stereo Vienna Instruments is the limit for my 8-core set; when mixing and for general playback, I have not yet reached the a limit.

Raising the buffer to 256 helps, but the latency is unbearable. By the time I get to 20+ stereo Vienna Instruments I actually have to draw the events in the piano roll window, because performing new parts is simply impossible.

So, my questions are: Does this happen on all new Macpro systems? If not, how can I make Logic evenly distribute the processor power as well as it does during playback, when I compose / perform during playback?

Thanks

Thanks for the advice. I just experimented with using VE instead of VI and I agree that overall it does lower the processing power.

But the Buffer setting in the Server Interface window is very strange. If my Logic buffer is set to 32 for example and the Server Interface buffer is set to x2 there is practically no cpu usage at all when playing back 12 or 16 stereo matrixes and I can perform over the top without using any more cpu. But if I select x1 Buffer - my god! I immediately max out core 8 just like before.

Its amazing that changing the buffer by such a tiny amount could cause such instability. I need to do more tests.

Also - I can't work out how to open the VE application in stand alone mode. Nothing happens if I double click on it