The UT/LT P35, X38 and X48 boards all share the same GTLREF design at board level regardless of BIOS labeling. The first GTL Reference Voltage option in the BIOS supplies processor lands H2 and F2. The second option supplies lands H1and G10.

Dual core processors:
Core 0 - Second listed GTL option in the BIOS
Core 1 - First listed GTL option in the BIOS

Quad core processors:
Core 0, 2 - Second listed GTL option in the BIOS
Core 1, 3 - First listed GTL option in the BIOS