As the title suggest, I accidentally installed 64-bit Ubuntu 13.04 in a 32-bit processor, and it is working fine for now (actually I feel my PC became more responsive). Will there be any problem in the near future though? I think my Motherboard is a 64-bit but I'm not certain, but my processor is a 32-bit. Further, I did lscpu and I got this:

Architecture:          x86_64
CPU op-mode(s):        32-bit, 64-bit
Byte Order:            Little Endian
CPU(s):                1
On-line CPU(s) list:   0
Thread(s) per core:    1
Core(s) per socket:    1
Socket(s):             1
NUMA node(s):          1
Vendor ID:             GenuineIntel
CPU family:            15
Model:                 4
Stepping:              9
CPU MHz:               2659.023
BogoMIPS:              5318.04
L1d cache:             16K
L2 cache:              1024K
NUMA node0 CPU(s):     0
  • 21
    According to the lscpu, your Processor is 64bit.
    – Mitch
    Jun 27, 2013 at 13:53
  • 1
    If everything works then you have a 64-bit CPU, then don't worry...
    – Alvar
    Jun 27, 2013 at 14:26
  • 5
    if you have 32 bit processor, 64bit OS will not even install
    – Dee
    Jun 27, 2013 at 14:38
  • Pentium F4 or Pentium D which are both Intel 64 – NetBurst microarchitecture (according to the CPU Family 15, Model 4 information). The D was a dual core processor, so that's probably not yours.
    – JustinC
    Jun 27, 2013 at 17:38
  • Very few, if any, PCs (and I am using that term broadly here) sold in the last several years have CPUs that are not 64-bit capable. And as has been pointed out in answers, your CPU is 64-bit capable, as evidenced both by the output quoted as well as the fact that it works at all.
    – user
    Jun 28, 2013 at 7:15

4 Answers 4


If you installed a 64-bit OS your CPU is necessarily 64-bit capable. In a 32-bit only processor the 64-bit installer not even starts.

In lscpu output CPU op-mode(s):32-bit, 64-bit means your CPU is both 32-bit and 64-bit capable. Architecture: x86_64 is the current kernel architecture (64-bit).

You can also check 64-bit support running:

grep " lm " /proc/cpuinfo

If it outputs nothing you have a 32-bit CPU. If it outputs something like flags : blah blah lm blah blah blah your CPU supports Long Mode (AKA 64-bit).

  • 2
    I did the grep "lm" /proc/cpuinfo and I got flags blah blah lm blah blah, thus satisfying your check.
    – Adnan
    Jun 27, 2013 at 14:39
  • 7
    There's no blah on my flags. Should I worry? Jun 28, 2013 at 1:00
  • 1
    @ruda.almeida blah = "a lot of flags you don't need to worry about". lm is the flag that tells you have a 64-bit CPU. Jun 28, 2013 at 1:08

From your output it is clear that you have a 64bit CPU. The line CPU op-mode(s):32-bit, 64-bit means that you have a 64bit CPU.

Therefore there is no problem using a 64bit OS.

  • 1
    A lot of times laptops with 64-bit-capable CPUs come with a 32-bit OS anyway (since they often have too little memory for 64-bit to be very useful). This is probably the source of the confusion. Jun 27, 2013 at 16:34

Looks like you experienced the same surprise I did a few years ago.

I accidentally put a 64-bit Ubuntu CD in my laptop and installed it, and a bit later I realised "Wait a moment.... I thought my laptop was a 32-bit system?"

If the 64-bit version works on your system, then that means your system is actually a 64-bit system, rather than a 32-bit one as you used to think ;)


Your processor is actually 64-bit processor as this line states:

Architecture: x86_64

If it has been 32-bit, you couldn't have installed a 64-bit OS in the first place. Don't worry, your PC will work just fine.

  • 6
    Actually Architecture: x86_64 means there is a 64-bit kernel running. The CPU architecture is shown in line CPU op-mode(s). Of course, a 64-bit kernel wouldn't run in a 32-bit only CPU, so this answer is not wrong. Jun 27, 2013 at 14:31

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