Uhm no I don't know...
The Abit support team has sent me this version and said it was the last bios available for this board.
Filename is "m704b_15.bin" and it was inside a rar file: "IX38 QuadGT15.rar". I didn't rename anything...
When I check CPU-Z it states that the BIOS build date is: "25/11/2008 (dd/mm/yyyy)".
I think the "m704b_16.bin" is an unofficial user-edited BIOS for this board but my version is made
by Abit programmers because I got the mail and attachment from: support@u-abit.eu