Solaris 10 X86 and Intel Core i5

Hi all,

we have a system running Solaris 10 X86 on an Intel Core i5 520.

Alltough the CPU has 2 cores (4 threads) the Solaris system only recognizes 1
single core, psrinfo gives:

# psrinfo -pv
The physical processor has 1 virtual processor (0)
x86 (chipid 0x0 GenuineIntel family 6 model 37 step 2 clock 2400 MHz)
Intel(r) Core(tm) i5 CPU 520 @ 2.40GHz


Any idea what could be the reason why there's only one CPU available to
Solaris system?

Thanks a lot,
Christian