X3220

why ssh #:cat /proc/cpuinfo     shows -  model name: Intel(R) Xeon(R) CPUX3220  @ 2.40GHz, but bellow I get cpuMhz 1600.00 ?

I opened the cpu from mobo S3200sh and it is X3220 quad core 8mb cache , the same ssh tells me cache 4mb.