The first line is a text string set-up by your motherboard's BIOS,
while the second line is NetBSD's own decode of the CPU signature
based on the CPU_ID. I don't have my decode-sheet handy to tell
which is correct.
Based on the fact that the BIOS seems to have gotten the clock speed
wrong, I'd suspect it also got the CPU model wrong. (An updated
BIOS might be able to decode the more-modern CPU_ID.)
It's an i7, but the Xeon version of it (which was model number 3520, I
think).
NetBSD sometimes does get the CPU speed correct, from a different
dmesg output:
cpu0 at mainbus0 apid 0: Intel 686-class, 2672MHz, id 0x106a5
No idea why or when it changes though.