To quickly retrieve the CPU information of a machine that is running on CentOS (or a similar flavor of linux) you can read off of the /proc/cpuinfo file using the cat command.

Example:

$ cat /proc/cpuinfo
processor       : 0  
vendor_id       : GenuineIntel  
cpu family      : 6  
model           : 58  
model name      : Intel(R) Xeon(R) CPU E3-1240 V2 @ 3.40GHz  
stepping        : 9  
cpu MHz         : 3400.157  
cache size      : 8192 KB  
physical id     : 0  
siblings        : 8  
core id         : 0  
cpu cores       : 4  
apicid          : 0  
initial apicid  : 0  
fpu             : yes  
fpu_exception   : yes  
cpuid level     : 13  
wp              : yes  
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 syscall nx rdtscp lm constant_tsc arch_perfmon pebs bts rep_good xtopology nonstop_tsc aperfmperf pni pclmulqdq dtes64 monitor ds_cpl vmx smx est tm2 ssse3 cx16 xtpr pdcm pcid sse4_1 sse4_2 x2apic popcnt tsc_deadline_timer aes xsave avx f16c rdrand lahf_lm ida arat epb xsaveopt pln pts dts tpr_shadow vnmi flexpriority ept vpid fsgsbase smep erms  
bogomips        : 6800.31  
clflush size    : 64  
cache_alignment : 64  
address sizes   : 36 bits physical, 48 bits virtual