Which sample rate should I use w/ Xonar STX? Better performance at 96?, [was “Which default sample rate for my sound card ?” in General Audio] Options

[extrabigmehdi]

Hello,
before I was doing in my dsp chain in foobar:
sox set to 96 khz , followed by a big vst chain of dsp tweaked to my taste.
But I've realized that overall my dsp were performing worse than with 44.1 khz.

So now it's more like :
big dsp chain followed by sox set to 96 khz.

Why upsampling ?
My reasoning:

- the default sample rate of xonar stx after install is 96 khz

- I imagine that if I use different software, with different sample rate, they must be mixed to a single sample rate at one moment.
So I rather set a big sample rate on soundcard, and play music at that sample rate.

- the measurements at tech report website, indicate that the xonar stx perform better at 96 khz , than 44.1 khz.
for 44.1 khz : http://techreport.com/articles.x/17256/8
for 96 khz: http://techreport.com/articles.x/17256/9

- if I don't upsample , and set the default sample rate to 96 khz, I imagine that the upsampling
would be either handled by the windows mixer or the driver of sound card ?
So I rather use something that is well tested like sox.
I'm not sure if wasapi would bypass resampling by system.

- I can hear differences, but if you ask me to verify such claim, I don't know how it could be ABX ed.

Here are sample rate supported by soundcard:
44.1 khz, 48 khz, 96 khz, 192 khz

So which sample rate would you use , and why ? Since even tech report website indicate that the xonar stx perform better at higher sampling rate, is is pertinent to upsample using sox "on the fly" while playing music , or should I leave this work to the driver/soundcard/ windows mixer/ I don't know .
Does wasapi allow to bypass upsampling if the the sample rate set on soundcard doesn't match sample rate of played music ?

thanks

[lvqcl]

- the measurements at tech report website, indicate that the xonar stx perform better at 96 khz , than 44.1 khz.

Do they? Or they indicate that 16 bits (44.1/16) is better than 24 (96/24)?