Enabling dual core support

I noticed the performance change in my computer in both of this configurations, and I just wanna get the best of my system. Some of you, then may ask. So, ¿ why don't you install the 64-bit version in the first time ? Well, I did, but it was impossible for me to install mentor IC Station because it does not have 64-bit compatibility yet.

I have an AMD 4200+ Athlon64 X2 EE and here works dual core support. I needn't do anything to get it work.

Please check the file /proc/cpuinfo (terminal command "cat /proc/cpuinfo"). There should be written detailed information about your cpu configuration. Maybe the system monitor doesn't display the correct information.

I just did what you told me and it shows a single core configuration. Specifically here is the infomation I got:

processor : 0
vendor_id : AuthenticAMD
cpu family : 15
model : 107
model name : AMD Athlon(tm) 64 X2 Dual Core Processor 4000+
stepping : 1
cpu MHz : 1000.000 <== I did this on purpose
cache size : 512 KB
physical id : 0
siblings : 1
core id : 0
cpu cores : 1 <== LOOK AT THIS !
fdiv_bug : no
hlt_bug : no
f00f_bug : no
coma_bug : no
fpu : yes
fpu_exception : yes
cpuid level : 1
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 rdtscp lm 3dnowext 3dnow pni cx16 lahf_lm cmp_legacy svm extapic cr8legacy 3dnowprefetch ts fid vid ttp tm stc 100mhzsteps
bogomips : 2011.06
clflush size : 64

Hm. Strange. How did you change the MHz? Maybe you changed also the numbers of core to use there?

I changed that simply using cpufreq-selector

Somewehere I saw that it have something to do with the kernel, but the question is, why I didn't have dualcore, then I do, and finally don't again. Please help me with this issue.

Okay. This is very strange. Maybe you can try to boot up the LiveCD and take a look if it detects both cores or also just one.

Please try to boot up the LiveCD and have a look if it detects both cores. This might be a bug or a hardware failure ...

Again, without any particular reason, the dual core support for my 32-bit OS is enabled. I guess this will remain as a mistery until somebody experiment the same thing but resolve it by her/himself.