I use Linux as my OS because less layers are involved when playing music. I use realtime kernel so as to secure the best result. According to the Real-time Linux Wiki, SMI badly affect the realtime performance (https://rt.wiki.kernel.org/index.php/HOWTO:_Build_an_RT-application). I therefore download the BITS from Intel (http://biosbits.org/) to test the SMI latency on my AMD and Intel system (except the MoBo and CPU, others are the same). The result is:-
Intel: Gigabyte P45 + E7200 C2D = ~550us
AMD: Gigabyte 785G + Athlon 64 x2 5200 = ~220us
Besides, when I browse through the survey on DPC latency in this forum, I am impressed that AMD produced better result (correct me if I am wrong).
On this basis, does AMD better perform Intel in terms of audio playback? Or are these results irrelevant if I turn off all the power management in BIOS?