Z170 Extreme7+ random Dr. Debug codes

I see now that you haven't built a PC system in over ten years? No offense, that would take us back to the Pentium D processors days (my first real build) and the various 900 chipsets. Much has changed since then.

For example, about six years ago, Intel moved the DRAM memory controller to the CPU. With that the mother board had less influence on memory operation and performance than in the past. Intel's processor technical documents now include the DRAM memory specifications, including the size and configuration of the memory chips that may be used, as well as the configuration of the memory chips on a single DIMM circuit board. The role a mother board plays in memory performance is not the same as it was in the past.

The UEFI/BIOS is of great importance regarding memory, so that could be looked at as the mother board still being of significance regarding memory usage.

Let's not forget that for Skylake processors like your i7-6700K, Intel guarantees a maximum DDR4 memory speed of 2133. Any memory speed above that is considered an OC, and we are on our own:

http://ark.intel.com/products/88195/Intel-Core-i7-6700K-Processor-8M-Cache-up-to-4_20-GHz

Skylake i5 and i7-6000 series processors are the first mainstream type that can support a maximum memory size of 64GB of memory. Note that Intel states that is "dependent on memory type".

The more memory used with a Skylake processor, the more difficult it will be to operate it at over clocked speeds. The higher the speed of the memory, the more difficult it will be to use two DIMMs per channel.

Checking our board's Memory Support List, we find that as the memory speed increases, the number of DIMMs per channel increasingly goes to only one DIMM per channel. Above DDR4 3200 speed memory, there is only one model that allows two 4GB DIMMs per channel. At DDR4 3600, some memory may be used as one DIMM in single channel mode.

http://www.asrock.com/mb/Intel/Z170%20Extreme7+/?cat=Memory

The highest speed memory where four 16GB DIMMs is listed is 2400. While new models of 16GB memory will be released that allow four to be used at 2400 or possibly higher speed, they will remain scarce.

You mentioned you don't yet know how to change the memory voltage and speed on this platform. It is very important to be able to do that when trying to get large amounts of memory operating at higher speeds. DRAM voltage adjustments alone are not enough, the VCCSA (System Agent) and VCCIO voltages will also need to be adjusted.

You can use your memory's XMP profiles as examples of what voltages are increased and by how much. First check the DRAM, VCCSA, and VCCIO voltages with the memory at 2133 (stock) speed. Then enable the XMP profile, and check the values again.

No one can tell you with 100% certainty if two randomly mixed sets of your Corsair 16GB DIMM 2400 memory will be able to work together. Someone using the same CPU, board, and two sets of your memory that is successful can give you a pretty good indication that you can do the same. But the memory controller in your CPU may not be as good as that person's, or their memory sets may be more closely matched by luck.

If you want the best possible guarantee that the Corsair memory you know works at high capacities will also work for you, get the set of 4 x 16GB DIMMs.