Hi, and tank you for your answer
So...I'm using esata (burst rate 50Mo/s+), with TY 16x, Verbatim MCC004 or Panasonic MBIPG101 R05 medias (usually give good burns with this burner (when burned "inside my computer"))
I tried 3 different PSU, 12V 2A and 12V 3A, and with 3 different drives (Optiarc AD-7240S, SH-S223F, Asus DRW-2014L1T). Asus and Samsung drives were able to achieve 16x burns with 3A power supply, Optiarc not (8x ok, 12x ok). Using external enclosure for esata and computer sata power cable, Optiarc was able to achieve even 24x burn.... seems like something wrong with enclosure logic board, isn't it ?