Created attachment 32972 [details]
lshw

I have a Phenom II X6 booting 2.6.35.4 on Ubuntu.
On disabling 4 cores (hey, I only need 2 unless I'm doing some hardcore number crunching) the system wouldn't boot at all - showing a message that related to that it couldn't find the cores and would therefore halt.

cpuinfo:

processor	: [[0-5]]
vendor_id	: AuthenticAMD
cpu family	: 16
model		: 10
model name	: AMD Phenom(tm) II X6 1055T Processor
stepping	: 0
cpu MHz		: 800.000
cache size	: 512 KB
physical id	: 0
siblings	: 6
core id		: 5
cpu cores	: 6
apicid		: 5
initial apicid	: 5
fpu		: yes
fpu_exception	: yes
cpuid level	: 6
wp		: yes
flags		: fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ht syscall nx mmxext fxsr_opt pdpe1gb rdtscp lm 3dnowext 3dnow constant_tsc rep_good nonstop_tsc extd_apicid aperfmperf pni monitor cx16 popcnt lahf_lm cmp_legacy svm extapic cr8_legacy abm sse4a misalignsse 3dnowprefetch osvw ibs skinit wdt cpb npt lbrv svm_lock nrip_save
bogomips	: 5631.41
TLB size	: 1024 4K pages
clflush size	: 64
cache_alignment	: 64
address sizes	: 48 bits physical, 48 bits virtual
power management: ts ttp tm stc 100mhzsteps hwpstate [9]

lshw attached.