INTEL
The following processors implement the Intel 64 architecture:
- Intel NetBurst microarchitecture
- Intel Core microarchitecture
- Intel Xeon (all models since "Woodcrest")
- Intel Core 2 (including Mobile processors since "Merom")
- Intel Pentium Dual-Core (E2140, E2160, E2180, E2200, E2220, E5200, E5300, E5400, E6300, E6500, T2310, T2330, T2370, T2390, T3200 and T3400)
- Intel Celeron (Celeron 4x0; Celeron M 5xx; E3200, E3300, E3400)
- Intel Atom microarchitecture
- Intel Atom 200 series (not to be confused with the N200 series, widely used in netbooks)
- Intel Atom 300 series
- Intel Atom N4xx, N5xx series
- Intel Atom Dxxx series
- Intel Nehalem-Westmere microarchitecture
AMD
AMD64 implementations
The following processors implement the AMD64 architecture:
- AMD Athlon 64
- AMD Athlon 64 X2
- AMD Athlon 64 FX
- AMD Athlon II (followed by 'X2', 'X3', or 'X4' to indicate the number of cores, and XLT models)
- AMD Opteron
- AMD Turion 64
- AMD Turion 64 X2
- AMD Sempron ("Palermo" E6 stepping and all "Manila" models)
- AMD Phenom (followed by 'X3' or 'X4' to indicate the number of cores)
- AMD Phenom II (followed by 'X2', 'X3', 'X4' or 'X6' to indicate the number of cores)
http://en.wikipedia.org/wiki/X86-64
Linux Find If Processor / CPU is 64 bit / 32 bit ( long mode ~ lm )
Example - Find Out If Running Kernel Is 32 Or 64 Bit
$ uname -a
Linux ora100 2.6.5-7.252-smp #1 SMP Tue Feb 14 11:11:04 UTC 2006 x86_64 x86_64 x86_64 GNU/Linux
x86_64 GNU/Linux indicates that you've a 64bit Linux kernel running. If you use see i386/i486/i586/i686 it is a 32 bit kernel.
How Do I Find Out CPU is 32bit or 64bit?
$ grep flags /proc/cpuinfo
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 ht tm pbe nx lm constant_tsc pni monitor ds_cpl vmx est tm2 ssse3 cx16 xtpr lahf_lm 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 ht tm pbe nx lm constant_tsc pni monitor ds_cpl vmx est tm2 ssse3 cx16 xtpr lahf_lm 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 ht tm pbe nx lm constant_tsc pni monitor ds_cpl vmx est tm2 ssse3 cx16 xtpr lahf_lm 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 ht tm pbe nx lm constant_tsc pni monitor ds_cpl vmx est tm2 ssse3 cx16 xtpr lahf_lm
CPU Modes:
- lm flag means Long mode cpu - 64 bit CPU
- Real mode 16 bit CPU
- Protected Mode is 32-bit CPU
http://www.cyberciti.biz/faq/linux-how-to-find-if-processor-is-64-bit-or-not/
https://help.ubuntu.com/community/32bit_and_64bit