I'm currently running in this machine, an SC-420, a P-4, 3.0Ghz, 800FSB, LGA-775 and it boots with the "Hyper-Threading" note on the Intel Logo at the POST screen.

 

Device manager is reporting "TWO" processors.

 

This was NOT a Dual-Core / Core-Dual processor.  SL8Q7 Intel P4 3.0/800/2mb