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

    DSInt

      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:

      ~22000MB/s

       

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

      ~15000MB/s

       

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

      ~12000MB/s~

       

      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.

       

      Thanks.

       

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