Crucial DDR4-2133 32GB Dual-Channel Memory Kit Review
For our memory overclocking tests we are usually interested in two main elements: how well the memory scales with additional voltage and how versatile it is at overclocking with different timings. While we usually cap memory voltage to 1.40V during our DDR4 overclocking endeavours, with this memory kit we had to limit ourselves to 1.35V because 1.40V caused errors in Hyper PI. Thanks to this static voltage, we were able to put all our efforts into determining timings scalability.
In order to make sure that there weren’t any possible CPU-related bottlenecks, the CPU VCCIO was set to 1.275V and the CPU System Agent Voltage set to 1.35V. Our ASUS Maximus VIII Extreme does not handle memory speeds above DDR4-3733 very well when using 8GB modules, but we don’t expect that to be a limitation in this case despite the even larger modules. We focused on four basic timing configurations (13-13-13 / 14-14-14 / 15-15-15 / 16-16-16) with a 1T command rate in order to maximize performance.
With the pleasantries out of the way, let’s get to the fun stuff.
Given the fact that we are dealing with large 16GB modules with a base speed of DDR4-2133 we didn’t have the highest expectations in the world, but in the end this memory kit proved to have a respectable amount of overclocking headroom.
As you can see, at the tightest timings, we were able to hit DDR4-2460, which is pretty good compared to stock. While there was surprisingly little difference between 13-13-13 and 14-14-14, once we loosened the timings to 15-15-15 these modules started to stretch their legs and we were able to hit DDR4-2733, a full 600Mhz over stock at stock timings. Further loosening the timings to 16-16-16 gave some additional headroom up to DDR4-2870. While we confident that we would be able to hit the DDR4-3000 level at CAS 17, it was regrettably not meant to be. We did attempt 17-17-17, but we just barely crossed the DDR4-2900 mark, and even then stress testing stability wasn’t great. We tried testing the modules individually, and the results were roughly the same. Loosening the command rate to 2T did not yield any additional overclocking headroom either.
If we compare these overclocking results to those our previously tested quad-channel Crucial DDR4-2133 32GB (4x8GB) kit, the differences are interesting. While this newer kit achieved a much better result at 15-15-15, the reverse was true when it came to 14-14-14 results, and even the 13-13-13 results were a tiny bit worse. Difference sized modules, different ICs, and even different platform, but still an interesting comparison.
These screenshots are just to prove that we did indeed achieve the overclocks listed, and that they were stable enough to pass a series of mainstream benchmarking and stress testing applications. If you are doing super critical work, then maybe a little Prime95 stress testing should be done as well, but for gaming and day-to-day tasks our approach is more than sufficient.
Check out the next few pages to see our benchmarking results. We kept CPU frequencies as close to 4.40Ghz as possible and increased the Cache/Uncore frequencies to around 4.10Ghz to try an eliminate any memory bandwidth bottlenecks. We were able to keep all four configurations within these guidelines, with only a 10Mhz variation in CPU frequency.