You can see detail in file /proc/cpuinfo. If you find “lm” (long mode) flag that mean your server can run 64 bit Kernal 
.
Example
| processor : 0 vendor_id : GenuineIntel cpu family : 15 model : 6 model name : Intel(R) Pentium(R) D CPU 3.40GHz stepping : 4 cpu MHz : 2400.000 cache size : 2048 KB physical id : 0 siblings : 2 core id : 0 cpu cores : 2 fdiv_bug : no hlt_bug : no f00f_bug : no coma_bug : no fpu : yes fpu_exception : yes cpuid level : 6 wp : yes flags : fpu vme de pse tsc msr pae mce cx8 apic mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe lm constant_tsc pni monitor ds_cpl vmx est cid cx16 xtpr lahf_lm bogomips : 6787.68 |
Woww
http://developer.intel.com/design/processor/applnots/241618.htm
http://processorfinder.intel.com/List.aspx?ProcFam=528&sSpec=&OrdCode
