[LABO] AORUS Z790 Tachyon


A very nice Christmas gift from AORUS as they have offered us a copy of the AORUS Z790 Tachyon motherboard to end this year in style. There has been some excitement around this board for a few days now as some users have been disappointed with the performance of the ROG Maximus Z790 APEX in retail version. On our side, we didn’t encounter any problem with the sample we received. This Tachyon Z790 version is very much awaited and many people imagine that it will be available in the next few weeks. We talk about an availability at the end of December in the shops even if it is not yet officially published on the brand’s website.

Thanks to AORUS for this sample and let’s discover directly in details what the unboxing of this motherboard dedicated to overclocking and cold testing has in store for us.

The bundle:

A little tour through the bundle of this AORUS Z790 Tachyon to see if it benefits from “special items”. Overall, we find a pretty standard bundle with the traditional SATA cables, Wi-Fi antenna, stickers, etc.

In the end, for a card dedicated to overclocking, this is not what interests us most. Note however that in my sample received, there is no manual of the motherboard, which is quite surprising.

The architecture:

The AORUS Z790 Tachyon motherboard is built around Intel’s latest chipset, the Z790. This motherboard retains the previous generation socket, the LGA-1700, as the processor has grown in size since the Rocket Lakes. With this Z790 version, this is the third Tachyon motherboard to be launched. The first one was built around the Z590 chipset, and it’s a board designed by Hi Cookie, the famous overclocker who manages the manufacturing and debugging of BIOS.


The Z790 chipset supports PCIe 5.0 offering higher storage performance than the previous generation as well as DDR5 support.

The various heat sinks:

The dimensions of the board are 305 mm x 270 mm, which corresponds to the E-ATX format. The dominant colors on the PCB are black and gray. The design of this “Tachyon” version is still quite special. Aesthetically, it looks quite similar to the Z690 version, but it is mainly the part dedicated to the buttons for overclocking that is organized differently.

Let’s start the tour with the radiators, of which there are three!
First of all, the two radiators located on the top of the motherboard and which surround the socket. They cover the power supply stage and are connected by a heat pipe. Note that the left radiator has a part that covers the external connectors. You will be able to see this better when disassembling the board a little later in the article.

The third one is the one that covers the chipset and that benefits from a rather large surface but a low height in order to easily allow the installation of the graphic cards.

The AORUS logo and a very light RGB backlight are present. We are here on a completely passive system.

Four SSD slots :

Two aluminum plates, whose cut-out perfectly matches the one on the chipset, cover the four M.2 SSD slots on the PCB. As you can see, the SSD slots all have a thermal pad to optimize heat dissipation. Without a manual and information on the AORUS website, it is very difficult for us to know how they are wired.

As soon as we have the information, we will of course update this unboxing. By the time this article is published, it should be.

The socket and PCIe :

The space around the socket is very well cleared and it will be quite easy to isolate it with rubber for testing under LN2. On the other hand, the card only has mounting holes for LAG-1700.

This Tachyon should logically support dual channel memory kits up to 7800 MHz+ (OC) and for a maximum amount of 64 GB. As you can see, there are only two memory slots. This is deliberate since the idea is to overclock the memory as much as possible, which is easier with two slots than with four. Remember that this card is 100% intended for overclocking. The two slots are far enough apart to be able to use a cooling kit under LN2.

There are two PCIe 5.0 ports which we unfortunately have no information on at the moment. To power all this, the card has a 24-pin flat connector and two 8-pin connectors next to the power stages.

AORUS seems to have reworked the retention system that releases your graphics card. This was a concern we had with the previous generation when a heat sink was too close to the first PCIe slot. We’ll be watching closely in our test to see if it works better.

The tools for clocking:

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

  • The Clear CMOS button: allows to clear the BIOS settings in order to return to the default ones.
  • The reset button: allows to restart the motherboard in case of failure.
  • The 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.
  • The Q-Led: it displays a code corresponding to the component responsible for the error during the boot. It has a larger size than on the previous versions.
  • The voltage points : allows to measure voltages with a multimeter directly on the PCB.
  • The power button: allows to power on the motherboard.
  • The LIMP mode (the turtle): similar to the ” safe Boot ” at Asus, this button 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. The board will then reboot with default settings.
  • The CPU Ratio Switch button: allows you to directly increase or decrease the multiplier of your processor.
  • The SB switch: allows you to disable or enable the Dual BIOS function.
  • The BIOS switch: allows you to switch between the two bios. You can thus choose to have an ” overclocking ” bios and a more stable bios for a H24 configuration
  • The TGR switch: a button a bit like the ” slow mode “, it will allow you to decrease the processor frequency and thus lower the CPU temperature before launching a benchmark and thus increase the chances that it will pass. You activate it, the temperature decreases, you put it back in its original position just before launching your benchmark.
  • The OC_IGNITION switch: it allows overclockers and DIYers to pre-test water cooling systems when building their computers without having to boot the system.

As you can see, the tools are numerous! I can’t wait to test each of them in a small session in the cold.


Let’s move on to the PCB, this one is built in 10 layers as indicated by an inscription on the corner of the PCB. This Z670 Tachyon is based on a 15 + 1 + 2 phase power supply.

The first controller used is a Renesas RAA2291131 which directly drives the 15 phases dedicated to the CPU. The 15 CPU mosfets are all Renesas RAA220105 of 105A. The GT part is managed by 1 Renesas RAA220105 of 105A. The IMC and PCIe part is managed by 2 MPS MP87992 of 70A. We are on a power supply stage similar to that of the Z690 Tachyon.


The rear panel has the following elements. First of all the LIMP mode (the turtle) also present on the PCB as well as the button allowing 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.

Regarding the USB ports, we are waiting to receive the specifications from AORUS so we can tell you more about them. Then we find the antenna supports for the dual band Wi-Fi and the audio part. Finally, we also find an HDMI port very useful to test the graphics chipset integrated into some processors. We have now completed the tour of this AORUS Z790 Tachyon, it’s time for us to test it and see you soon to discover the complete test here.