One Motherboard, Two Faces – ASUS ROG Maximus Z690 Apex review with Teardown, RAM- & Adaptive Core-OC

1 - Introduction and Preface 2 - Design-Overview and Features 3 - Teardown and PCB analysis 4 - BIOS overview and other test hardware 5 - ROG True Voltitian and in-OS Software 6 - DDR5-OC - mainboard batches compared 7 - Adaptive By-Core OC and Conclusion

BIOS and test hardware used

As you would expect from Asus, there are more tuning options in the BIOS than any enthusiast or overclocker could ever want. We have to praise Asus for not resting on their laurels, but continuously developing the BIOS and its features with every motherboard generation.

Probably the best known feature is the calculation of the Silicon Prediction (SP) value, which we also used recently when binning 30 Alder Lake CPUs. For this, the VID table programmed into each individual CPU by Intel is read and, with a bit of math and statistics, a prediction is made about the silicon quality and thus the overclocking potential of a CPU. A higher value is better, at least theoretically and when comparing CPUs with identical frequencies at the V/F points.

But Asus has also included numerous other features for this generation of boards, some of which I would like to briefly introduce to you. One of them is the High DRAM Voltage Mode. DDR5 modules are known to have an integrated voltage converter (PMIC), which is responsible for converting 5 V to the various RAM voltages such as VDD and VDDQ. JEDEC limits this to a maximum of 1.435 V in the standard, so many PMICs do not want to supply more than this, even though they could. This is exactly where this option comes into play, with which even PMICs that are actually locked can be made to supply up to 2.07 V to the RAM chips. For example, SK hynix OEM DDR5-4800 modules can be overclocked to well over 6000 Mbps using a JEDEC-limited PMIC from Renesas.

As is known, another innovation in DDR5 and Alder Lake are the 32-bit subchannels and the two separate IMCs (Integrated Memory Controllers) of the CPU. As a result, each subchannel also has its own RTL (Round Trip Latency) timings, which are negotiated during memory training. The Z690 Apex is currently the only board that can also adjust the RTLs on the subchannel level.  

Equally practical is the CPU information read out, such as the signature and the corresponding microcode used. The availability of AVX-512 in Alder Lake CPUs has been a hot topic since their launch. Enthusiasts would like to use the instruction set for more performance and efficiency, but Intel does not officially support it and has put a stop to the feature starting with Microcode version 18. Asus also has to bow to Intel’s decision here, but at least the active version can be read directly in the BIOS. And even if Asus only provides new BIOS versions with the new microcode, resourceful users can still code an old microcode into the BIOS and thus keep AVX-512 alive.

When you hear the word microcode, many will think of Non-K OC, i.e. overclocking Alder Lake CPUs without a free multiplier, recognizable by the “K” suffix of the SKU. Asus were the first to exploit a loophole in early microcode to also allow overclocking of such non-K CPUs by increasing the BCLK. Probably because of this, the dedicated BCLK buttons have finally made it onto the motherboard in this generation. Asus has effectively breathed new life into an entire overclocking category with this feature, and I’d like to tip my proverbial hat to that!

At most, Asus could be criticized for creatively renaming some BIOS options, which ultimately only leads to confusion for users of different motherboard manufacturers. For example, the CPU VDDQ voltage is called “IVR Transmitter VDDQ Voltage” and the VDD2 voltage is christened “Memory Controller Voltage”. With other manufacturers and HWinfo, the voltages are then called differently again and chaos is pre-programmed.

A new BIOS version is still available from Asus almost every week almost half a year after the launch of the Z690 platform. And even though these versions are usually not supported and only rarely make it to the official website, they are a thankful matter for enthusiasts and hobbyists – including a direct mouthpiece to the Asus BIOS development team. You can find them in the forum of HWbot or Overclock.net, which I link here. The BIOS versions used in today’s test are 9902, 0070 and 1301, all no older than 4 weeks. However, due to the high release frequency, it is not possible to run all tests on the same version without excluding any fixes in new versions. I think this compromise of multiple versions with intermediate plausibility tests is therefore the fairest.

Now I have a tabular overview of all the hardware used in the test for you: