Test System

Test System

Testing Rated Speeds

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.

Crucial's Ballistix Elite 2666 MHz DIMMs boot into the BIOS with a default 2400 MHz. To enable the full 2666 MHz profile, enable XMP, which in some instances, like with our reference X99 DELUXE, results in the system's BCLK being set to 125 MHz, while the memory multiplier is set to 2133 MHz. When this happens, the results are a 2666 MHz memory speed and, perhaps, slightly boosted CPU and cache speeds, depending on the motherboard you use. While this posed no problems for me, there have been some reports of issues with Crucial memory as of late, and it might simply be explained by these two facts. Not all motherboards can run the 2666 MHz multiplier with 100 BCLK, and not every CPU likes running 125 BCLK. BE that as it may, a quick call to Crucial's support line should help get any issues you run into sorted as these sticks do feature a lifetime warranty.