BIOS Settings for Overclocking

In this chapter, I'll give you a brief overview of the BIOS (UEFI setup program).


Make it a rule of thumb to control all the voltages you can find in the AI-Tweaker tab manually since the voltage auto-tuning algorithms for most boards are still far from ideal. In my case, the VDDG and PLL voltages had a mind of their own, which prevented the system from running stable. The voltage steps for the CPU, SoC, and VTT DDR are as fine as 0.00625 V. For DRAM, it is 0.01 V, which for me was an unpleasant surprise. Quite often, a very fine adjustment of the DRAM voltage is required, which unfortunately isn't possible on the ASUS ROG Zenith II Extreme. There are also some oddities with software that monitors the DRAM AB and CD channels. It reported different voltages for each channel, sometimes with a variation as high as 0.015 V, while when tested manually with a voltmeter, voltages were exactly the same between channels, even at 1.5 V.


The next important menu is Digi+ Power Control. It greets the user with numerous settings, where one of the most important is "CPU Power Phase Control," which needs to be set to "Extreme mode" so you can use all 16 phases. Surprisingly, the CPU Load-line Calibration (LLC) in auto mode worked perfectly; VDroop was nearly absent in non-AVX loads, so I decided to keep it on auto and let it do its job. LLC is represented by 10 different levels ranging from -2 to 8. Of course, the higher the level, the greater the load compensation. Such a large variety of levels allows each user to find the settings that work best for them. Meanwhile, the CPU Switching Frequency has an adjustable range from 250 to 1000 kHz, which also allows for fine-tuning when required.


As previously mentioned, the ASUS ROG Zenith II Extreme has settings with which to configure the mode of operation for PCIe devices, starting from the interface bus bandwidth and ending with the PCIe generation. Also, in the Onboard Devices Configuration menu are settings for audio and network controllers.


All the way on the bottom are the settings that allow you to control the RGB lighting for the system when it's on or off.


The last important item for us is "Monitoring." Despite its name, it not only allows you to monitor the onboard sensors, fans, etc. You can also easily configure the operation modes and fans of the VRM, chipset zone, two pumps, and a pair of PWM connectors; I used the two PWM connectors for two 140 mm fans that cooled the DRAM zone, which was very handy.


I'm not going to consider PBO modes in my material as AMD practically abandoned this feature. Max CPU Boost Clock Overdrive, promised by AMD's Robert Hallock as a special feature of Zen 2, is still working in "Alpha" mode, and manual changes of the EDC, TDC, and PPT limits led to an unreasonable increase in TDP with a mediocre increase in CPU frequencies. I wouldn't call this a working feature but rather classify it as a demo feature that offers user a minimal all-cores boost beyond the point of diminishing returns instead of increasing the boost properly. Turning off PBO manually does not enable the alternative PB2 mode in which the temperature curve and the FIT voltage limiter act as limits. Apparently, PB2 is still completely broken.


AI Suite 3 is a very useful proprietary utility for several adjustments right in your operating system. Use it to adjust the processor frequency, voltage on various components, or, as there are unfortunately no FAN hub adjustment options in the BIOS, fan speed with the FAN Extension Card II.