I am using this motherboard with Dual 18c Xeon E5 2686v3. Memory is 6x16GB Samsung ECC reg 2133MHz ( M393A2G40DB0-CPB ). Memory is properly populated according to motherboard manual.
Problem I face is i don't get any memory bandwidth increase when running 6x memory (3 for each CPUs, also tried 4 sticks into slots conmected to CPU1 and 2 sticks for CPU2)
I have done AIDA64 memory read-write-copy test multiple times.
2x memory installed = read speed is approx 31GB/sec. (1 stick for each CPUs).
3x memory installed = read speed is approx 32GB/sec. (2 sticks for CPU1 and 1 for CPU2).
4x memory installed = read speed is approx 60GB/sec. (2 sticks for each CPUs).
5x memory installed = read speed is approx 62GB/sec. (3 sticks for CPU1 and 2 for CPU2).
6x memory installed = read speed is approx 62GB/sec. (3 sticks for each CPUs).
I have flashed multiple BIOS but i get similar performance. Tried few built-in presets like memcached and mWeb. Also tried with NUMA enabled and disabled.
Memory bandwidth in 6ch is similar to as in 4 channels.
Is there any fix for it or i will have to buy 2 more sticks to make total of 8 sticks, so it will work in 8 channels ?
According AIDA64 memory benchmark Dual E5 2660v3 gets approx 105GB/s memory read speed with 8x DDR4 1866R.