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I use Debian squeeze on a Toshiba Satellite. I want to know FOR SURE if my CPU is a 64 bit or a 32 bit. I ask this here because I am now very confused. What follow are the outputs of four different bash commands that allow the user to query exactly that (width of the CPU):

grep getconf LONG_BIT returns 32;

grep /proc/cpuinfo returns

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 amdc1e nonstop_tsc extd_apicid pni monitor cx16 popcnt lahf_lm cmp_legacy svm extapic cr8_legacy abm sse4a 3dnowprefetch osvw ibs skinit wdt nodeid_msr

and this says that if lm appears highlighted then my CPU is 64-bit; well, it's not highlited.

lshw returns two different things: 32-bit motherboard and 64-bit processor (I saw this post here and I thought that the answer applied to my case. Does it?)

And finally, lscpu returns:

Architecture: i686

CPU op-mode(s): 64-bit

CPU(s): 1

Vendor ID: AuthenticAMD

CPU family: 16

Model: 6

Stepping: 3

CPU MHz: 800.000

Virtualization: AMD-V

L1d cache: 64K

L1i cache: 64K

L2 cache: 512K

In conclusion: what's the conclusion here? Is my CPU a 32-bit or a 64-bit? I know I installed the 32-bit (i386) kernel, but that aside I need to know what my processor is. Thanks in advance. Cheers!

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One other sure-fire way to check would be trying to boot an x64 LiveCD. It'll complain really quickly about a lack of 64-bit support. Honestly though, if the machine was made in the past five years, it's going to be 64-bit, especially if it has virtualization features. – Charles Nov 8 '12 at 6:39
all AMD CPUs from opteron (2003) and later supports x86_64. No modern x86 CPUs are 32-bit only – Lưu Vĩnh Phúc Sep 13 '13 at 5:29
up vote 0 down vote accepted

This is a generic commmand for all Linux distros :

grep -q '\<lm\>' /proc/cpuinfo && echo "My CPU is a 64 bits one" || echo "My CPU is a 32 bits one"

It's a hardware information : you can run a 32bit distro on a 64bit PC. The command will reveal the truth.

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It returns 64. So is that the true width of my CPU? – Óscar Guajardo Nov 9 '12 at 18:28
Yes, that's it AdbekunkusMX – Gilles Quenot Nov 10 '12 at 20:04
Thanks everyone and please excuse the obsesivity. Cheers! – Óscar Guajardo Nov 11 '12 at 22:11

According to this page on the Gentoo wiki, your CPU (Family 16, Model 6, Stepping 3) is 64-bit.

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