Perfoamance contention not seen in autonomous multiprocessor system

Hi ,

I am conducting a test to check the performance of my code. the code on both the processor are the same.

I kept one processor system to be constant as Nios II/E and other with various configuration.

say Nios II/F I-cache 2KB 4KB 8KB and with D - Cache of 2KB 4KB and 8KB.

When I run the test, say for example CPU 1 with Nios /E and CUP2 with Nios II/F with I and D cache of 2KB i get the result for the code perfomance.

but when I conduct a number of test by varying CPU2 configuration and keeping CPU1 same , I see that the CPU1 gives me the same result irrespective of the CPU2 configuration.

Can any one please help me out in this, as why there is no contention seen in performance of CPU 1 (I.e CPU 1 performance values remains same) while changing CPU 2 configuration.

I am using a performance counter to measure my code on both CPU's.

thanks

anand