Tweaking for Speed

With testing out of the way, I endeavored to see if these sticks have any headroom. For Intel, I kept the same procedure I have been using, leaving all settings at their XMP defaults and then increasing the frequency until the system loses stability. After finding that limit, I manually tweaked for the maximum frequency and lowest possible timings. Voltage modification from stock is allowed. After all, this is overclocking!

The 11th Gen Intel Core processor paved the way for things to come with the introduction of the memory controller Gear ratio that allows the system memory to run in a synchronous 1:1 mode with the CPU memory controller, or a 2:1 ratio. Intel 12th Gen Alder Lake brought DDR5 support along with an additional 4:1 ratio and continuing DDR4 support.

The 1:1 ratio generally stops between 3600 and 4000 MT/s for Alder Lake CPUs. My Core i9-12900K maxes out at 4200 MT/s, which isn't rare if going by the sheer number of forum posts about many struggling to reach 3800 MT/s. It is safe to say that anything greater than 3600 in a 1:1 ratio configuration is completely dependent on the CPU memory controller.

With this information, Intel 12th Gen Alder Lake paired with DDR5 will gain the most from the highest-possible frequency without giving up the benefit of the increased bandwidth it can provide. Because DDR5 generally has a higher operational frequency, synchronously operating it in 1:1 is unlikely. That only leaves 2:1 as a viable option for any DDR5-based setup. The motherboards should automatically switch to the 2:1 ratio. If all else fails, you can manually set this in the BIOS.

Intel Results

With the Intel Core i9-12900K, this kit mimics the other Micron kits in my possession. Using the XMP settings, I was not able to raise the frequency past the default 5200 MT/s profile. Going down in latency also ended in a failed boot sequence.

After this quick failure, the next step was to raise the CAS to 40, which had it boot and pass stability tests at 5400 MT/s. Raising the speed to 5600 MT/s reported minor errors which then required 1.35 V to stabilize. Up to 5800 MT/s was bootable, but completely unstable. For reference, I know that 6400 MT/s is possible with this ASUS ROG Z690 Hero and my CPU, which has me hoping that someone without enough patience will bring this XPG Lancer kit under control if 5800 MT/s is their end goal.