Tell me more ×
Super User is a question and answer site for computer enthusiasts and power users. It's 100% free, no registration required.
up vote 2 down vote favorite

I have a Lenovo Ideapad Y510. I have always used 32bit OS in it. Yesterday I came across this detail of my laptop and it says processor of my laptop is 64bit (hope I have not misinterpret anything) so I did some google and I came across this question. As I have Ubuntu installed I tried command in last answer (i.e lscpu) and output was same with some differences. My main concern are first two lines of output i.e.

Architecture:          i686
CPU op-mode(s):        32-bit, 64-bit

My question is does my CPU support 64bit OS? As per this link I think yes.

If yes then shouldn't be the output of lscpu be like samothing as below as far as I know i686 stands for 32bit. Correct me if I am wrong.

Architecture:          AMD64
CPU op-mode(s):        64-bit
share|improve this question
Of course, you could have just downloaded a 64-bit "live" CD, and just tried... ;-) – DevSolar Jul 19 '12 at 8:53

3 Answers

up vote 4 down vote accepted

Yes it does support 64bit OS.

It has two entries because on 64-bit processor you can install both 64 and 32 bit ubuntu.

share|improve this answer
thanx for clarifying the two entries meaning. – Sandy Jul 19 '12 at 7:34
Do all 64-bit processors run 32-bit Ubuntu? E.g. IA-64 Itanium? SPARC64? PA-RISC? s/64-bit/x86-64/ – RedGrittyBrick Jul 19 '12 at 9:18
@RedGrittyBrick it is actually answered in the itanium wiki article you linked :) You CAN run 32 bit ubuntu on those, but they will be painfully slow. – Sandro Dzneladze Jul 20 '12 at 7:28
up vote 1 down vote

The output you saw from lscpu means your processor (Google says it has an Intel Core 2 Duo) is capable of 32-bit and 64-bit, but that you are currently running a 32-bit operating system.

The output from a 64-bit operating system is:

Architecture:          x86_64
CPU op-mode(s):        32-bit, 64-bit

You should be fine to install a 64-bit operating system if you wish.

share|improve this answer
up vote 1 down vote

To know if the installed Ubuntu is of 32 or 64 bits:

  • getconf LONG_BIT
  • uname -m

If it shows i686 or i386 it means 32-bits.
If it shows x86_64 it means 64-bits.

If the CPU is 32 bit, Ubuntu must also be 32-bit.
If the CPU is 64 bit it can work with 64- or 32-bit OSes. We can choose to install 32- or 64-bit Ubuntu.

To know if the CPU is of 32 or 64 bits:

  • grep -w lm /proc/cpuinfo
    • If we see lm in red, the CPU supports 64 bit. Otherwise it is 32 bits.
  • sudo lshw | grep “description: CPU” -A 12 | grep width
    • It says clearly what we want to know.
share|improve this answer

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.