Review : ROG Maximus Z790 APEX


The PCB and connectors:

The tools for clocking:

Let’s start with the elements inserted on the PCB and which can be interesting tools for overclockers. There are a lot of them on this model, which has become a habit with Asus on the high end. This confirms its position as a card dedicated to overclocking.

  • The power button: allows to power on the motherboard.
  • The FlexKEY (reset) : allows to restart the motherboard in case of failure. The button can now be assigned to another task via the BIOS.
  • Safe Boot: allows to restart the board even if the parameters chosen in the bios do not allow the boot. This avoids having to do a CMOS Clear to reboot and thus lose your encoded settings.
  • ReTry Button : during cold tests, sometimes the OS freezes and a reset does not allow to restart the motherboard : only solution 6, 7 seconds by keeping the START button pressed. With the ReTry button, it restarts immediately.
  • Switch bios : allows to switch between the two bios. You can choose to have an ” overclocking ” bios and a more stable bios for a H24 configuration.
  • Slow Mode: allows you to boot with a 16x coefficient and once in the OS to put back the one chosen in the bios. It is especially for max screens.
  • RSVD: when activated under cold conditions (-120°C), it avoids ” Cold boot bug “.
  • LN2 Mode : allows to activate LN2 profiles in the bios.
  • The debug LED: 4 diodes (CPU – DRAM – VGA – BOOT) which allow to diagnose errors during the boot of the board. If one of them stays on, it means that the corresponding component has a problem.
  • The Q-Led: allows to display a code corresponding to the component responsible for the error during the boot.
  • The CMOS CLR: allows to erase the BIOS parameters in order to return to the default ones.
  • ProbeIT : allows to measure voltages with a multimeter directly on the PCB.

The PCB:

Our Asus Maximus Z670 APEX is based on a 24 + 2 phase power supply. The part in charge of the CPU consists of 24 phases and on this model, no doubler, but beware the phases are placed in parallel: they are really 12. The controller is a RAA229131 chip(X+Y=20), one of the best currently if not the best.

The 24 mosfets are all RAA 22010540 of 105A grouped in parallel by phase and thus allow to duplicate them without using a doubler. The mosfets in the power stages generate the most heat because they are responsible for the voltage conversion and delivery to the CPU from the 12 volt EPS connector.

The connectors :

The rear panel has the following elements. First of all the Clear CMOS and the button to flash the bios from a USB key. One of the particularities of the card is to have two PS/2 slots to connect a keyboard and a mouse. But why still use this type of connector in 2021? Simply because some benchmarks are more powerful under XP (Super Pi) and the use of non-USB peripherals greatly facilitates the installation of the OS.

In terms of USB ports, this ROG Maximus Z690 APEX has four USB 3.2 Gen 1, five USB 3.2 Gen 2 and one USB 3.2 Gen 2 Type-C. Then we find the antenna supports for dual band Wi-Fi. The audio part is provided by a SupremeFX ALC4080 chip. Finally, we find the various audio outputs and the network port (2.5G).