welcome on board, Neva22...
Gary explained it already, but I'll add a couple of pieces for an even more complete picture:
Intel tries to get 2 birds with one stone - energy efficiency (to reduce heat) when the CPU is idle (or close to idle) and powerboost when it's under heavy load.
This scheme is supposed to fit the needs of most
average users - and is based on permanent powerswitching and shutting off 'unused' parts of the CPU.
As Gary mentioned you will have to shut that off (most likely) if you do
real time processing, and that's what the talk was about, which you didn't understand. Don't worry - I didn't understand it either when first reading about it.
You could just turn off a number of USB ports in Bios and check the documentation of the board to which physical connectors they belong...
or simply plug in an USB memory stick and watch on which connectors it's recognized by the OS.
If less IRQ are allocated before Windoze boots, it's more likely that it has an IRQ free for the card.
Most USB audio devices use codecs, which are general designs to a/d d/a conversion on a single chip
(codec is an abreviation for encoder-decoder and means to encode analog signals by digitizing them plus decoding the digital data into an analog signal for playback sound)
Many are plain rubbish, some are decent, very few are really good...
regarding 'famous mic-preamps' ... well, that's just kidding folks who never had the opportunity to access a real good preamp.

(marketing blurb, you guessed it)
I have 2 pres that are considered a very good design (Telefunken V676a to be precise) and I can assure you that 'just' a proper powersupply improved their (already great) tone significantly.
Opposed to that USB devices are either supplied by noisy powerlines from the PC or cheapo wallwarts...
cheers, Tom
(Gary was faster...)