playback mps-5 v dcs puccini

You should get the USB-X box.

Get a Mac Mini with SSD and load it up with memory. Run some optimization to cut out unwanted background processes and dedicate the machine for music playback. Run Audirvana+ with Direct/INT mode and a good USB cable (I am using Cynosure from Locus)

IMHO it's getting to the point where the computer is about equal if not exceeding the built in transport.

thanks for your suggestions Doggiehowser. I have decided to get hold of an USB-X box, then investigate the computer side. I have a mac pro and a macbook pro at the moment.

I think as long as the machine is dedicated and you can disable background processes