AnsweredAssumed Answered

imx6s vs imx6q memory bandwidth difference

Question asked by Dennie de Groot on Apr 24, 2018
Latest reply on Apr 24, 2018 by igorpadykov



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.


CommandiMX6 SoloiMX6 Quadcore
bw_mem -P 1 -N 4 128M rd1417.691318.39
bw_mem -P 1 -N 4 128M wr467.34373.44
bw_mem -P 1 -N 4 128M rdwr486.82397.27
bw_mem -P 1 -N 4 128M cp460.50342.82
bw_mem -P 1 -N 4 128M fwr2178.06370.24
bw_mem -P 1 -N 4 128M frd1158.55622.61
bw_mem -P 1 -N 4 128M fcp768.31317.41
bw_mem -P 1 -N 4 128M bzero2175.32339.56
bw_mem -P 1 -N 4 128M bcopy770.06355.44


Does anyone know why there is such a big difference between the Solo and Quadcore with identical DDR configuration?