Every week TechARP discusses a different BIOS option, this time they reveal the functionality of the FPU OPCODE Compatible Mode. You can learn about it over here.
This BIOS feature determines how Pentium 4 and Xeon processors handle FOP codes using the FOP (final opcode) register.
When enabled, the Pentium 4 and Xeon will engage the FOP code compatibility mode, which stores the FOP of the last non-transparent instruction in the FOP register.
When disabled, the Pentium 4 and Xeon will turn off the FOP code compatibility mode and store only the FOP of the last non-transparent floating point instruction that had an unmasked exception. This allows for better FPU performance.
Therefore, it is recommended that you disable this feature for better FPU performance unless your software requires this feature to recover from FPU exceptions.