LinuxQuestions.org - Linux x86 and (64bit)

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Linux x86 and (64bit)

Hi all
I have basic question about:

1. What is Linux x86
2. What does (64 bit) mean and how can I identify my server is 64bit or not?

Thanks ...

x86 = 32 bit
x86-64 = 64 bit

if you have an AMD 64 bit processor then you want to use a 64 bit linux (x86-64)
otherwise just an x86 flavor

Quote:

Originally Posted by taxtropel (Post 3065745)

x86 = 32 bit
x86-64 = 64 bit

if you have an AMD 64 bit processor then you want to use a 64 bit linux (x86-64)
otherwise just an x86 flavor

Thanks...
But I have another question :
I want to identify my servers bit Where I must look for it? Or which command I must use to identify first :
1. My servers processor type
2. My installed Linux versoin with processor (am I installed 32 bit or 64 bit)

Thanksss

type uname -m to get your servers processer type

Quote:

Originally Posted by AceofSpades19 (Post 3065794)

type uname -m to get your servers processer type

Yes
I typed uname -m and it gived me i686. THen, my server's CPU is 32 bit.. Am I right?

And another question. How can I define my installed Linux version. Is it 32 bit or 64?

Thanks

Quote:

uname -m

gives the os(32bit/64bit).

Quote:

cat /proc/cpuinfo

Gives the cpu.

In my case I am running a AMD X2-3800 with 64bit Fedora 8.

Quote:

[fred@localhost ~]$ uname -m
x86_64
[fred@localhost ~]$ cat /proc/cpuinfo
processor : 0
vendor_id : AuthenticAMD
cpu family : 15
model : 43
model name : AMD Athlon(tm) 64 X2 Dual Core Processor 3800+
stepping : 1
cpu MHz : 2015.003
cache size : 512 KB
physical id : 0
siblings : 2
core id : 0
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 rep_good pni lahf_lm cmp_legacy
bogomips : 4031.25
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

processor : 1
vendor_id : AuthenticAMD
cpu family : 15
model : 43
model name : AMD Athlon(tm) 64 X2 Dual Core Processor 3800+
stepping : 1
cpu MHz : 2015.003
cache size : 512 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 rep_good pni lahf_lm cmp_legacy
bogomips : 4029.82
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

hey there. just thought i will add a quick note. since you established that you are running i686 architecture, pretty much it would be impossible to run an x86_64 version of any kind of Linux, because i doubt it would install in the first place. but in case you need to run both 32 bit and 64 bit applications, then you most definitely would want to upgrade to a 64 bit architecture. because on a x86_64 system you can run both 32 bit and 64 bit, but not the other way around. peace.

Quote:

Originally Posted by Ejdaha (Post 3065741)

2. What does (64 bit) mean

The AMD64 and Intel EMT64 CPUs support two different (but related) instruction sets. In one, integer and address registers are 32 bits, in the other integer and address registers are 64 bits.

The most important difference is that 32 bit addresses support a 4Gb virtual space, part of which it reserved by the OS, so an individual task can only use about 3Gb of virtual memory. The addresses in 64-bit mode don't support a virtual address of the full 4G squared, but they do support more virtual address space than anyone could reasonably use.

If the OS is 64 bit, each program can be either 32 bit or 64 bit. But if the OS is 32 bit, even on a CPU with 64 bit support, all programs must be 32 bit.

Quote:

Originally Posted by taxtropel (Post 3065745)

if you have an AMD 64 bit processor then you want to use a 64 bit linux (x86-64)
otherwise just an x86 flavor

I'm not sure of the pro and con factors to that choice. But most experts seem to advice differently than the above, saying:
If you have more than about 4Gb of physical ram, the PAE option that lets a 32-bit OS manage it is a bit messy so the 64 bit OS is a better choice.
If you need an individual program to take more than 3Gb of virtual memory (physical ram plus swap space) then you need the 64 bit OS.
If neither of the above is true, most expert advice I've seen says to use the 32 bit OS.