Currently I am developing on 2 custom boards with a identical layout. The difference is the used processor.
One board has a iMX6S and the other board a iMX6Q processor. Both boards have the same DDR configuration so the chips (MT41K128M16JT-125:K) and layout (32-bit) are identical. The DDR on the boards are independently calibrated.
However when running "bw_mem" (part of lmbench) I get very different results as the table below shows.
The 'bzero' test for instance is 6x slower on the Quadcore then on the Solo.
|Command||iMX6 Solo||iMX6 Quadcore|
|bw_mem -P 1 -N 4 128M rd||1417.69||1318.39|
|bw_mem -P 1 -N 4 128M wr||467.34||373.44|
|bw_mem -P 1 -N 4 128M rdwr||486.82||397.27|
|bw_mem -P 1 -N 4 128M cp||460.50||342.82|
|bw_mem -P 1 -N 4 128M fwr||2178.06||370.24|
|bw_mem -P 1 -N 4 128M frd||1158.55||622.61|
|bw_mem -P 1 -N 4 128M fcp||768.31||317.41|
|bw_mem -P 1 -N 4 128M bzero||2175.32||339.56|
|bw_mem -P 1 -N 4 128M bcopy||770.06||355.44|
Does anyone know why there is such a big difference between the Solo and Quadcore with identical DDR configuration?