If you are experiencing performance issues after consulting all other troubleshooting tips, then the following should be considered. For example, if you are playing a few tracks with the clock source set to PCI-324 Internal, but you encounter artifacts in the audio when you are sure this file is clean.

The PCI-324 card is a Busmastering device due to the high bandwidth it uses on the PCI bus. On a Macintosh with six PCI slots there are two busses: slots 1-3 are assigned to one bus while slots 4-6 are assigned to the other. If possible you should place the PCI-324 card on a bus that is not being shared with another busmastering device. You may want to consult your computer's technical supplement for slot numbering. On UMax computers, the busmasters can reside in either Slot 1 or 2. You should place the PCI-324 card in one of these slots if you have a UMax machine. This will provide the optimal performance when using your 2408.