The Host Buffer Multiplier (found under the Setup menu > Configure Audio System > Configure Hardware Driver) improves performance in Digital Performer version 4 and later when using more than one hardware driver.

When you are using multiple CoreAudio drivers simultaneously, set the Host Buffer Multiplier set to 2.

Note that when you are using a PCI-324 or 424 system with multiple interfaces connected to the PCI card, the Host Buffer Multiplier should still be set to 1. This is because although you are using multiple interfaces, you are still only using one driver.