Hi, I bought a Sapphire 270x 4gb version last week (SAPPHIRE R9 270X 4GB GDDR5 WITH BOOST & OC), bios version is: 015.044.000.012.000000.
Here is the bios file: http://www.mediafire.com/download/58eqi0xkyt6yhcy/Pitcairn_270x_Sapphire_4gb_bios.bin
It was dumped with Sapphire TRIXX, hope it is helpful