How to find out in Linux if yours is a 64-bit Processor?

For sometime now I've been working on a low-cost Celeron M 530 1.73 GHz notebook by Compaq. I faintly remember the manual I got with this notebook mentioned somewhere that it's though economic, it's 64 bit processor.

Last night I wanted to try a Mepis 8 64-bit. But before that I started doubting if Intel just made a false proclaimation of this CPU cos it's just a Celeron chip.

In my search across several linux forums to find out if Celeron M 530 is a 64-bit chip I met with 4 commands that tell about the PC's architecture out of which 3 just talked about the architecture type of the installed OS, and only one told about the processor type.

First, I issued command arch

$ arch
i686

No clue about the CPU type, it returned architecture of the installed kernel.

Second, I tried uname

$ uname -a
Linux localhost 2.6.26.8-tex3 #1 SMP Mon Apr 20 17:37:07 EDT 2009 i686 Intel(R) Celeron(R) M CPU 530 @ 1.73GHz GNU/Linux

Again, it told about the installed kernel type, not the CPU.

Third, somebody told me to tray getconf

$ getconf WORD_BIT
32

This command also mentioned about the kernel type - 32 bit.

Finally, I came to know that /proc/cpuinfo only reflects about the Processor type. However, sometime the information is not explicit.

Here is the contents of my /proc/cpuinfo

$ cat /proc/cpuinfo

processor : 0
vendor_id : GenuineIntel
cpu family : 6
model : 15
model name : Intel(R) Celeron(R) M CPU 530 @ 1.73GHz
stepping : 10
cpu MHz : 649.998
cache size : 1024 KB
fdiv_bug : no
hlt_bug : no
f00f_bug : no
coma_bug : no
fpu : yes
fpu_exception : yes
cpuid level : 10
wp : yes
flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss tm pbe nx lm constant_tsc up arch_perfmon pebs bts pni dtes64 monitor ds_cpl tm2 ssse3 cx16 xtpr pdcm lahf_lm
bogomips : 3458.39
clflush size : 64

From the above type it's not crearly understood by the "model" or "model name" if the processor is 64-bit capable. However, the "flags" section of cpuinfo reveals it. Presence of the "lm" is only indicator of your CPU being 64-bit capable.

Thank God, I never knew this low-cost celeron m chip supports 64-bit computing. I am going to install Mepis 8 64-bit.