Overclocking - Didn't go as planned..

Overclocking the Intel 13900K CPU had a troublesome start this time. Using the same principle rules from the 12th generation Intel processors as a guide, the session started off the same with a baseline test at stock configuration to get the basics out of the way. Once done, it was time for the brute all-core overclock, simply because it is the easiest when constrained by time. Often undervolting and picking 2-cores for highest frequency will yield better results for power efficiency, but is it quite the undertaking to validate on each and every motherboard tested.

The first step here for an all-core overclock was going straight to 5.5 GHz (P-Cores) using only 1.25 V. This is where the stock CPU turbo sticks to when all cores are in use. Next step was to reach the end-goal of 5.8 GHz with a maximum voltage of 1.4. Right from the start the issues started, the Vcore droop was 0.05 V. Not a big deal until the CPU is in need of that last bit of power. Workaround to this problem was to raise the CPU voltage to accommodate the droop during load. This did not work out well because now during CPU idle, the voltage looked a bit high. Next attempt to remedy the problem was to change the PWM Switching Frequency to 1000 KHz. Turn off Load Line Saturation Control and change the Load Line Calibration to Mode 4 (Middle). A quick load test showed that now it has 0.10 V droop under load and a increase of 0.15 V above the set value while idle. This was worse!

This cat and mouse game continued for a bit while trying different LLC modes and voltages and ended up without a successful good daily-use overclock. Either the voltage was too high for idle, or was too high during load. Sudden jumps to 1.5 V in Cinebench R23 were not uncommon to see. This is far too high for daily use and normal watercooling setups. After a bit of troubleshooting, the entire overvolting problem was found to be directly related to the PWM Switching Frequency. With it back to 500 KHz, we did a full circle and back to step one.

CPU overclocking on this specific motherboard was not an enjoyable experience at all. There is far too many variables to say this MSI MEG Z790 ACE motherboard is not a good overclocker. Rather, it is safe to say that it may be a challenge to work with, depending on your CPU overclocking knowledge and understanding of MSI naming conventions and specific OC quirks.

Memory Overclock

DDR5-7200 HWBOT Submission Link

Memory overclocking wasn't as problematic, but still wasn't ideal either. By default, using BIOS 1.12 (Newest), the System Agent (SA) voltage will not surpass 1.2 V without manual intervention. This lower voltage is actually a good thing to see. In previous Intel Z690 and some Intel Z790 ones as well, this SA voltage would scale up forever, leading to some quite high numbers unknowingly to novice users. By putting a soft-cap on what is applied from using the default auto settings, it prevents degradation of the CPU's ability to run higher frequency memory. However, it does limit the maximum frequency just from enabling XMP.

What this means for the plug and play user base is that DDR-7200 is the limit here. The motherboard will boot all the way into Windows up to DDR5-7800, but immediately fails the memory stress tests. By manual adjusting of the SA, VDD2 and VDDQ_TX voltages, DDR5-7400 was stabilized. This took a lot of playing around with the sub-timings as well, since the motherboard auto training put some values quite low, causing y-cruncher 2.5 B to fail the benchmark. Overall, this means running high memory speeds is possible, but not something to recommend attempting without a good understanding of memory timings and the accompanying voltages. Otherwise, it possible to have an unstable system and not even know it.