Some tips on processor identification

Since I started using a 64-bit processor, I got these doubts. After installing a GNU/Linux in my AMD Turion 64 bit X2, I would like to know whether the installed OS is 32 bit / 64 bit OS. Thank you for Ananth Srinivas who pasted this information in one of the mailing lists. Just issue the following command in GNU/Linux:

$ getconf LONG_BIT

If you get '64' then the OS is a 64-bit one, else if you get '32' then it is a 32-bit OS. The second thing is, you have a machine with some 'x' type of processor. You want to know whether your processor is 64-bit capable. In order to find this you can put the following command:

$ cat /proc/cpuinfo

In the flags if you get something like 'lm', then it is a 64-bit capable processor. An example from my machine is:

processor       : 1
vendor_id       : AuthenticAMD
cpu family      : 15
model           : 72
model name      : AMD Turion(tm) 64 X2 Mobile Technology TL-50
stepping        : 2
cpu MHz         : 800.000
cache size      : 256 KB
physical id     : 0
siblings        : 2
core id         : 1
cpu cores       : 2
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 lm 3dnowext 
3dnow up pni cx16 lahf_lm cmp_legacy svm cr8_legacy
bogomips        : 1598.01
TLB size        : 1024 4K pages
clflush size    : 64
cache_alignment : 64
address sizes   : 40 bits physical, 48 bits virtual
power management: ts fid vid ttp tm stc

You may note that it is clearly visible from the above output that we have 64 shown at many places. But this is not the case with all the processors. In some Xeons we dont have such explicit identification, when this is the case then 'lm' in flags indicate that it is a 64-bit processor.