With DDR4 being an entirely new platform for new CPUs and motherboards, comparisons to bygone technologies prove an exercise in futility. I don't feel it's quite accurate to compare things without some sort of common denominator present, and compared to past test platforms, the only common item in my test system is the graphics card, a MSI GTX 780 GAMING. Adding in numbers from past X79-based systems wouldn't truly provide the right field for comparison either since the new Haswell-E CPUs offer a substantial performance increase over past X79 Express IvyBridge-E and SandyBridge-E CPUs. So the following numbers are from my current test platform only. Our CPU reviewer has already posted a comparison review for the CPU side of things.
There is also another subject to consider, and it must be mentioned, although it does have to do with CPU-related performance. Getting the most out of any DDR4 memory is only truly possible with some overclocking. Haswell-E CPUs communicate with the memory via their L3 cache whose speed is set dynamically by default. This means that cache speed at idle sits at 1200 MHz, but increases to much higher speeds at load, based on which CPU model you have. With my retail i7-5930K, speed at load is 3000 MHz. So in order to eliminate this aspect of the platform as a bottleneck, both CPU and cache speeds are increased under all testing conditions. As such, the performance offered by this product under stock configurations may differ from the numbers reported here.
Getting Crucial's kit up and running was no problem at all. Since its speeds are not associated with an XMP profile, simply installing the sticks and booting the system should see the Crucial sticks running at their optimal settings. I did test this on several motherboards other than the ASUS used in my testing today, and found that such was the case no matter which board I picked. I checked to verify that the sticks were running at their default 1.2V, which they were in every instance unless manual settings were applied to the BIOS after the first time I powered up a new system. +1 to Crucial for the ease of setting these up.