3 Replies Latest reply on Dec 14, 2016 2:34 PM by Intel Corporation

    i7-6700, Reduced memory performance with 4 (DDR3) modules compared to 2


      Hello, I have a performance problem:


      I have 4 same memory modules of:

      8GB DDR3L 1600 CL11 1.35v Dual-Rank

      with the i7-6700 processor.


      In my B150 motherboard (Asrock B150M Pro4S/D3) if I use 2 Modules in Dual-Channel mode I get the expected performance, but not with all 4.


      With 2 Modules (16GB) in dual channel "winsat mem" built-in windows 10 memory benchmark utility reports:



      If I use all 4 modules (32GB) in dual channel mode "winsat mem" reports:



      And just for comparison with 1 module in Single Channel mode:



      The performance difference is visible in various applications, not just that benchmark.


      Is this a CPU limitation or a motherboard problem?


      The processor documentation says that the skylake cpus has a total of only 4 memory rank controllers. Is this the reason for the performance degradation? All 4 modules have 8 ranks total.




      NOTE: There are no stability/reliability problems in both cases, this is just a performance issue.