I have two systems I've just built. They both have i7 processors and Asus P8Z77 motherboards. When I run a simple processor loop benchmark that I wrote in Delphi some time back I get one machine showing nealry twice as fast as the other. I then used CPU-Z to dump me the details of the hardware and I see that the fast machine shows:

Processor 1                     ID = 0
        Number of cores         4 (max 8)
        Number of threads       8 (max 16)
        Name                    Intel Core i7 2700K
        Codename                Sandy Bridge
        Specification           Intel(R) Core(TM) i7-2700K CPU @ 3.50GHz
        Package (platform ID)   Socket 1155 LGA (0x1)
        CPUID                   6.A.7
        Extended CPUID          6.2A
        Core Stepping           D2
        Technology              32 nm
        TDP Limit               95 Watts
        Core Speed              3610.7 MHz
        Multiplier x FSB        36.0 x 100.3 MHz
        Stock frequency         3500 MHz

the slow machine shows:

Processor 1                     ID = 0
        Number of cores         4 (max 8)
        Number of threads       8 (max 16)
        Name                    Intel Core i7 2600K
        Codename                Sandy Bridge
        Specification           Intel(R) Core(TM) i7-2600K CPU @ 3.40GHz
        Package (platform ID)   Socket 1155 LGA (0x1)
        CPUID                   6.A.7
        Extended CPUID          6.2A
        Core Stepping           D2
        Technology              32 nm
        TDP Limit               95 Watts
        Core Speed              1648.2 MHz
        Multiplier x FSB        16.0 x 103.0 MHz
        Stock frequency         3400 MHz

i.e the slow machine has a 2600k to the fast machine 2700k. The very different "Multiplier x FSB" must be significant but I dont understand how two processors with a very 'similar' number can be so different. To get the machines the same must I copy the processors or is there some clever setting that I can change?

Thanks for any help. Brian.