Can Macs play 5.1 surround sound??

I've read a post or two on here that say you need an external sound card or something in order to get 5.1 sound out of a Mac. I've also read on other forums, including one that's strictly about home theater with a subforum for Macs as HTPCs, that Macs can play surround sound on their own if you connect an optical cable using DVD Player, Quicktime, or VLC/Perian. You just need to make some settings adjustments to get it working.

So which is it?? I'm about to buy a DVI to HDMI and mini-toslink to toslink cables to connect my MBP (and soon a Mac Mini) and want to know if I'll get 5.1 out of my DVDs and other videos through my computer.

Thanks.

Yes using the optical out (toslink) you will get 5.1. Make sure to go into Audio Midi Setup in utilities and make sure it shows that you have 5 channel output listed.

Thanks.

so would something like this work for the MBP? http://www.amazon.com/QVS-10-Foot-Toslink-Mini-Toslink-Adapter/dp/B00007E87A