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!

This 3600 MT/s kit from Lexar is a good starting point for Ryzen builds, with 3600–4000 MT/s being optimal due to Infinity Fabric limitations. For those who are unaware, AMD Ryzen CPUs can benefit substantially from a 1:1 ratio being synchronized with the system memory and Infinity Fabric in many applications.

On the Intel side of things, 8th to 10th Generation Intel Core processors are going to benefit the most from the highest possible frequency with the lowest timings. That being said, 3733–4000 MT/s is the ideal target range since there is no need to play around with VCCSA/IO voltages, and for the most part it is Plug and Play. Switch to an 11th Gen Intel Core processor and things change given the introduction of the memory controller Gear ratio similar to what AMD already has done. Once you surpass the memory controller's ability to stay in synchronous 1:1 mode, most motherboards will automatically switch to 2:1 ratio. If all else fails, you can manually set this in the BIOS.

For the 11th Gen Intel Core i9-11900K used in this test system, the 1:1 ratio stops at a messy DDR4 3600. No matter the VACCSA/IO voltage or memory kit I use, this is the limit for this CPU. Any higher and I must switch to 2:1. Some have reported upwards of 4000 MT/s 1:1 support. I am not one of the lucky few.


On the Intel Core i9-11900K, I was able to achieve 1866 MHz with all other XMP settings at their default, which is a good result for a high-capacity kit. The downside is that I had to break the 1:1 Gear ratio, which actually hurt overall performance. If you can't keep it in line, it is best to leave it at the default XMP—an unfortunate outcome for 12th Gen Intel Core processor owners.


For AMD, I was able to achieve 1900 MHz stable with the Lexar Hades OC RGB on my MSI MEG B550 Unify-X with the XMP default timings. However, I was not able to tighten the timings at all. Any additional voltage threw up errors in stability tests, and lowering any primary timings failed to boot at 1900 MHz. However, I will take this 100 MHz increase over 1800 MHz (3600) as CL16 occasionally gave me errors, making that a failure as well. So the manual overclock actually is the same as the XMP overclock. DDR4-3800 is the limit of this particular kit I have. No extra voltage or shortening up the timings at either DDR4-3600 or 3800 was achievable.


Only minor gains were to be had as 100 MHz isn't a major jump in performance, certainly not when the primary timings are already so loose to begin with. The XMP OC and manual overclock look the same because they use identical timings in the charts. JEDEC comes in at 1600 MHz (3200) CL22. You will always want to enable the XMP profile if possible.