So with your big tirade above, did you even answer the question? What do those two links have to do with what you're asking?
The links are talking about linear power supplies. The problem is, it's the
entire motherboard that causes electical noise, emits EMI and other such issues like grounding loops from imperfect / imbalanced ground planes amongst the multiple layers.
Had you been paying attention, you'd have seen mention in the DIYAudio forums that most (if not all) of this noise is removed from PCI-connected audio cards that come with their own voltage regulation circuitry. If you have a $700 sound card, chances are the manufacturer spent at least a few dollars on building a proper VRM setup.
And if they didn't? You got ripped off, because even $50 PCI-based SoundBlaster cards have that kind of equipment.
This isn't a PC versus Mac thing; they're made up of the same electronics and will have the exact same problems. This is YOU buying a good sound card that has it's own filters, ground-loop isolation and RF shielding as to keep all the noise OUT from whatever system it's plugged into.
i bet you don know shit about windows sound driver hierarchy and stuff and yet , I have a bet where the 4000 posts of yours came from why in hell YOU have to comment about sometingh you haveno fckin clue ?
Can the attitude, ass. Windows sound driver hierarchy has
dick to do with the question at hand. But maybe if you too had a fckin clue, you'd already know that?