That's because that's what the BIOS is calling it

During POST, the BIOS stores the name of the CPU into some registers in the CPU, and all CPU-Z et al show for the "name string" is this string. So, when the BIOS misidientifies the CPU, the name string will be incorrect in these programs (and hence of very little use).
The *real* information for the chip (ie: that's hardwired into the chip and not inferred) in GCPUID's case is:
{} CPU Vendor
{} CPUID information (Family, Model, Stepping, Ext Model, Ext. Family and Ext Stepping only)
{} CPU speed and multiplier (only if PowerNow is not used)
{} Cache sizes
{} Instruction set support
Everything else is inferred from the above data, and is possibly incorrect.