With testing out of the way, it is time to see if this memory kit has any additional headroom. For Intel, we start off by using the XMP profile and increasing the frequency until the loss of system stability. After finding what can be accomplished without changing any of the timings or voltage, the second step can begin. This is where we go for the maximum frequency and lowest possible timings. Voltage modification above the XMP profile is allowed. After all, this is overclocking!

Intel's 11th Gen Intel Core processor paved the way for things to come. The introduction of the memory controller Gear Ratio allowed the system memory to run in synchronous 1:1 mode (Gear 1) with the CPU memory controller, or in a 2:1 ratio (Gear 2). With the release of Intel's 12th Gen Alder Lake based processors came DDR5 support and the additional 4:1 ratio (Gear 4).

It is generally considered that between 3600 and 4000 MT/s is the upper limit for Gear 1 support when using a Alder Lake (12th Gen Intel) CPU. This of course is partially dependent on the CPU memory controller and supporting voltages related to memory. In rare instances, higher-end motherboards can increase this slightly and offer better overall compatibility due to shorter trace length, higher PCB layer count and a better memory training algorithm. For instance the Intel Core i9-12900K used for these memory reviews maxes out at DDR4 4133 MT/s for single-rank memory. 4133 MT/s is quite a unlikely occurrence judging based on the sheer number of forum posts of many users struggling to get 3800 MT/s stabilized. It is safe to say that anything greater than 3600 MT/s using Gear 1 will often require a bit of hands-on tuning.

Since DDR5 has a higher operating frequency and a dual 32-bit data bus, synchronously operating it in 1:1 does not function at all. So far there have been no confirmed reports of this working for DDR5. That only leaves 2:1 Ratio and above as a viable option for any DDR5-based setups. The motherboard should automatically switch to the 2:1 ratio for both DDR4 and DDR5 above 3600 MT/s. If all else fails, you can manually enforce Gear ratios in the BIOS as well. With this information on hand, we can deduce that Intel 12th generation processors using DDR5 in theory will benefit the most from the highest-possible frequency, until the 2:1 ratio is not longer possible. At that point the cycle starts over again with a new 4:1 ratio and even higher frequency system memory.

Those looking to overclock on a Intel platform will generally find a hard barrier around 6600 MT/s using the Intel Z690 and Intel 12th Gen CPU. Switching to Intel 13th Gen, this value increases to 6800-7200 MT/s when using Intel Z690 motherboards and 7800-8000 MT/s for Intel Z790 4-slot motherboards. Special overclocking specific motherboards like ASUS Z690 Apex, Gigabyte Z690 Tachyon, MSI Z690 Unify-X, ASRock Z690 AQUA OC, and EVGA Z690 Dark can reach DDR5-8000+. While the new wave of Z790 versions start at DDR5-8000 and can reach up DDR5-9000+ with exotic cooling such as LN2.

Caution is advised when raising DRAM voltage over the rated XMP profile. Direct airflow or a waterblock may be necessary for long-term stability. This extends to the CPU as well. Raising the integrated memory controller voltage (vDD2), System Agent (SA), and VDDQ_TX above Intel specifications may cause irreparable damage. Please proceed with care and do research before attempting this. Do not copy and paste values without understanding the impact first, especially if simply taken from screenshots posted on Discord or Reddit.

When it comes to overclocking, things get a little bit complicated trying to understand all the technical terms and how they fit together. With the new AM5 socket, AMD has switched to DDR5 exclusively, leaving DDR4 behind. Those familiar with the ideal configuration from the previous platform can still apply some of the same overclocking principles here as well. Those new to the memory overclocking scene or need a refresher only need to follow a few rules to get started.

First is a quick refresher for AMD and DDR4. The ideal configuration for Zen 2 (3000 series) and Zen 3 (5000 series) based processors will always be to match the internal Infinity Fabric (IF) to the memory controller, which matches the frequency of the system memory as well. This is often referred to as a 1:1:1 configuration. Once the system memory exceeds the capabilities of the memory controller, a secondary system is in place to allow the memory to still function and operate by breaking this ratio. In doing so, the memory controller frequency is now cut in half, operating in a 2:1 configuration. This introduces a major latency penalty that negatively effects games that are memory sensitive with a measurable frame rate loss in some instances. AMD marketing uses DDR4-3600 as the "sweet spot" for Ryzen 3000 series, with DDR4-3800 best suiting Ryzen 5000 series processors. This is where cost vs. performance intersects, giving good results by using just X.M.P (A-XMP, DOCP, EOCP) DDR4-3600 profile and the motherboards auto settings. For the most part, this is a set and forget type of situation using single or dual-rank memory in the system for a total of two DIMMs. In the example above, DDR4-3600 in a 1:1:1 configuration would be 1800 MHz for all three. Generally speaking, ignoring outliers, 2000 MHz IF and DDR4-4000 RAM is the upper limit for this ratio when using an AMD Ryzen 5000 processor.

With the basics out of the way, we can talk about DDR5 and what to expect now that this new AMD (AM5) platform uses it exclusively. The AMD engineering team has changed the formula slightly from the ideal DDR4 configuration. The new "sweet spot" is now DDR5-6000, but with a twist. The Infinity Fabric (FCLK) is now independent and no longer is required to match the system memory for best results. In many instances a FCLK of 2000 MHz is the default value with a range "up to" 2133 MHz. It is highly suggested to leave this value at 2000 MHz, as higher frequencies often will outright refuse to work with a system hard-lock, requiring clearing the CMOS to recover. Even though some motherboard manufacturers have cited 2133 MHz as a possibility in media review guides, it may not be until the next CPU generation when we achieve these numbers consistently, without the aid of binned CPUs.

During the testing phase of different AMD motherboards and from observation while working on these reviews, it seems that for now DDR5-6400 and beyond will be out of reach for many users. AMD AGESA / BIOS updates have already increased compatibility, but it isn't perfect. The standard setup of a 2:1:1 ratio works seamlessly through DDR5-6000. While a wide range of AM5 B650 / X670 motherboards support DDR5-6400+, this frequency and above can be problematic. Often lowering the FCLK and / or changing the memory ratio to 2:2:1 (Gear 2) will help alleviate some configurations that are struggling to get stable, like four single rank DIMMs at DDR5-6200, but this may not help to stabilize DDR5-6400 and above.

Caution is advised with DRAM voltage over the rated EXPO / XMP profile. Direct airflow or a waterblock may be necessary for long-term stability. This extends to the CPU as well. Raising the integrated memory controller voltage above AMD specifications may cause irreparable damage. Please proceed with care and do research before attempting this. Do not copy and paste values without understanding the impact first, especially if simply taken from screenshots posted on Discord or Reddit.