What does sample rate matter on sound card?

I was looking at getting a decent sound card.
Pretty much down to 3 cards priced about the same and seem similar:

Ceative Soundblaster X-fi titanium (comes with powerdvd software)
HT Omega Striker 7.1

and the one most interesting right now:
ASUS Xonar 7.1

The first two have a 'sample rate' of 96khz,

while the Xonar has a 'sample rate' of 192 khz (which is the rate that the more expensive cards next step up (about double) have.

Does the 'sample rate' matter any? I cant find any info on this.
Anything anyone knows about any of these cards that fall into the category of 'Its great, except I cant believe they didnt include.....with it, so I cant use it'

Help greatly appreceiated.

chances are you wont wont notice any difference between the two
192khz is better but you would need an insane set of ears and good studio monitors to tell the difference.

unless you plan to make music id go with the x-fi titanium

Below is a simplified discussion on the concept of Analog to digital converter which is commonly used for sound quantization and reproduction.

Analog to Digital Converter

http://articles.moneycentral.msn.c [...] =1,1390081

Digital to Analog Converter

http://en.wikipedia.org/wiki/Digit [...] _converter

The quality of reproduction is dectated so many factors (not only sampling rate)
1)linear/non linear ADC
2) Accuracy
3) Quantization Error
4) Aperture Error
5) Sampling Rate
6) Aliasing
7) Oversampling
On So on...

Since the discussion is limited to Sampling rate. Below is the Nysqust Sampling Theorem which to summarize means

"to create an accurate reproduction of a signal (S) with highest freq component (f) the minimum sampling freq should be 2(f) but limited to sign(S)<(f).

"The higher sampling frequency will result to better signal reproduction"


http://en.wikipedia.org/wiki/Shann [...] ng_theorem