Hi, a little late but i confirm that my PCM driver works not so bad on my SGX (but really bad on mednafen,and maybe PCE) .
The bad noise/distortion i experienced with mednafen, seems not present on the real thing,or it's really not audible,it's hard to tell.
I'll really use this driver for my next devs on SGX as it use 5x less of CPU power than the classic brute force method for the same frequency .