The card we were waiting for the most, built around the latest Intel chipset, has just arrived at the editorial office: the ROG Maximus Z790 APEX from Asus. The resemblance with the Z690 APEX version is striking even if Asus surprised us by opting for a metallic grey PCB.
The APEX series represents the best from Asus for overclockers. The card has many tools implemented on the PCB and benefits from regular BIOS updates. The engineering team being very reactive, several BIOS are already available. If you want to get your CPU temperature below 0°C, this APEX will certainly prove to be one of the best choices for the Z790 chipset. The Raptor Lake processors have set a lot of records.
Thanks to Asus for making this sample available.
[nextpage title=”ROG Maximus Z790 APEX: “]
With each new generation of Maximus motherboards, Asus offers us an APEX model which represents the “ultimate” board for overclockers. So it was with some excitement that we started our tests, which focused mainly on the overclocking potential of the DDR5 memory.
The bundle:
A small tour through the bundle of this ROG Maximus Z790 APEX to see if it benefits from “special accessories”. And the least we can say is that there is quite a lot to show you!
For once, the bundle is a bit lighter and the “ROG True Voltician” oscilloscope is no longer present. On the other hand, there is a USB key containing the drivers, an SSD M.2 DIMM2 support as well as a PCIe card which has a slot for a hard disk in SSD M.2 format and PCIe 5.0 compatible. The point is that when these drives become available, you can add one to your configuration via this card. Currently no GPU or SSD is available in this standard.
A nice little accessory makes its entrance in this bundle, it’s a six digit padlock. It is not really a “real” lock, but this one was used to display the 8812.85 MHz frequency reached with an APEX Z790 and an i9-13900K which became the highest frequency ever reached with an Intel processor. Finally, we find the usual cables as well as a support and a fan that can be added to the power stage.
The architecture:
This is actually the fifteenth Maximus, one of the most famous models of the Asus brand. This one is of course part of the ROG (Republic Of Gamers) series. It seems that Asus no longer names the number of the series since the title on the box is Maximus Z790 APEX. We no longer have a reference to the number “XV”.
A quick word on the box, which becomes black and distinguishes itself from other models and previous generations by forgetting the traditional color code of the brand. The ROG Maximus Z790 APEX is built around Intel’s new Z790 chipset, which retains the socket of the previous generation with the LGA-1700 since the processor has grown in size since the Rocket Lake.
The Z790 chipset supports PCIe 5.0 offering higher storage performance than the previous generation as well as DDR5 support.
The different heat sinks:
The dimensions of the board are 305 mm x 244 mm, which corresponds to the ATX format. The dominant colors on the PCB are metallic gray and white. This is a radical change of color for the PCB. The design is still peculiar but on this version, the PCB resumes its rectangular shape. Aesthetically, it looks quite similar to the previous version of the APEX model, the Z690.
Let’s start the tour with the radiators, of which there are four!
First of all, the three radiators located on the top of the motherboard and surrounding the socket. The two largest ones cover the power supply stage. These two radiators are connected by a heat pipe.
A third, smaller, and also connected through a heat pipe is responsible for keeping the stage cool a part of the supply stage. We are here on an entirely passive system. The radiator stamped with the quote ” For those who dare “. It is composed of two parts and hides under the upper part, a slot for an SSD type M2 PCIe 4.0.
The fourth part is the one that covers the chipset and has a fairly large surface area but a low height to allow easy installation of graphics cards. The Asus ROG logo can be found there, which benefits from an RGB backlighting system.
No M.2 5.0 SSD on the PCB:
A white aluminum plate, whose cut-out perfectly matches the one on the chipset, covers an M.2 SSD slot on the PCB. As you can see, the SSD is sandwiched between two thermal pads. You also have the option of using the vertical bracket (ROG DIMM2), present in the bundle, which can also accommodate two M.2 SSDs. This brings the total number of M.2 SSDs to four, but they are PCIe 4.0 x4 versions.
If you want to use a Gen 5.0 slot, you will have to use the PCIe card in the bundle.
The socket and PCIe :
The space around the socket is pretty clear and will be easy enough to isolate with rubber for testing under LN2. Moreover, Asus offers two mounting holes on the ROG models. One of them is compatible with LGA-1700 but also LGA-115x coolers! A very good point for Asus.
This Maximus Z790 APEX can accommodate a maximum of two DDR5 memory bars. Who says new processors says at Intel new chipsets . At first, it is the Z790 chipset which will be available. Good news because this one keeps the LGA-1700 socket as well as the backward compatibility. In other words, you will be able to use an i9-12900K on the Z790 chipset and conversely, an i9-13900K on the Z690 chipset. Intel will continue to support DDR4 on this chipset but this should be the last time since the switch will be made definitively to DDR5 in 2024.
Like the Extreme version, this APEX has a button called Q-Release. When a card is plugged into the first PCIe slot, pressing this button opens the retention system and releases your graphics card. This was a concern we had with the previous generation when a heatsink was too close to the first PCIe slot. Good job Asus!
This APEX supports dual channel memory kits up to 8000 MHz+ (OC) and for a maximum amount of 64 GB. There are two PCIe 5.0 16x slots that will work in x8/x8 if you opt for SLI or CrossfireX. A third PCIe 4.0 x4 slot is also available as well as a PCIe 4.0 x1. To power all this, the card has a 24-pin flat connector and two 8-pin connectors next to the power stages.
RGB or not RGB ?
As is the case for a large part of the ROG range, it has the AURA system with LEDs present on the PCB at the level of the heatsink covering the connectors and the logo placed on the chipset. The management of these lights is set via the AURA software but it is possible to disable them, quite easily, via the BIOS if you wish.
[nextpage title=”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).
[nextpage title=”The BIOS:”]
As far as the BIOS is concerned, at first glance, we can see that we are at Asus. Those who are used to the brand will find it without any difficulty. As a reminder, the tab that will interest us the most is “Extreme Tweaker”.
Before starting, we remind you that it is essential to regularly update your BIOS. Moreover, the Asus team regularly proposes patches which it would be a shame not to take advantage of. The advantage of a card like this APEX is that it has two BIOS. You can test a new one while keeping the previous one. For those who are tinkering, this is a real plus! You can also save your BIOS on a USB key. You can then reload them after having updated your BIOS.
The BIOS captures were taken with the XMP profile of our Teamgroup Delta RGB 7200 MT/s CL34 kit enabled. The other new option is ” Memory controller: DRAM Frequency Ratio ” which arrived with Rocket Lake. You can choose between Gear 1, Gear 2 and Gear 4. Be aware that in most cases, it will be the Gear 2. The Gear 4 solution is there for kits > 7000 MHz.
The ” Loadline calibration ” is in auto mode for comparative tests but we will come back to its function when overclocking the i9-13900K. The other sections are present since the previous generations and allow you to flash your motherboard, to control the speed of the fans and to create test profiles.
The different voltages :
In the ” overclocking ” section, we will see the most important voltages for the CPU and for boosting the DDR5 memory. You should know that it is possible to deactivate the E-core but that the performance of your processor then takes a serious blow. We’ll tell you about it in the rest of the article.
Finally, saving profiles is highly recommended when performing tests. It saves time. You can also save them on a USB key.
With the arrival of memory kits with A-Die chips, Asus has added a new memory profile that can reach 7600 MT/s. We’ll be sure to test it during memory overclocking.
The LN2 mode :
We find a LN2 mode, which must be activated via a jumper placed on the PCB. Be careful, this one is really dedicated to cold tests, so don’t activate it for air/water tests as some safety features will be automatically disabled. Once this one is activated, there is a LN2 CPU profile.
A BIOS that continues to evolve :
Frankly, respect Asus! Already that the rate of updates and patches is excellent, the Asus team continues to evolve the BIOS by adding with the version of the BIOS Beta 0031, the presence of a second SP value which indicates the potential of the IMC of your processor. The higher this value is, the more your processor should be able to hold high frequencies with the DDR5 memory. We’ll talk about this again when we talk about overclocking DDR5.
We have already tested our i9-13900K and i5-13600K under liquid nitrogen but with our copy of the Maximus Z690 APEX. Don’t hesitate to ask for advice on our forum and discord if you encounter any problems when setting up your bios.
[nextpage title=”The test setup:”]
Here are the different components that equip our test platform. For the publication of these tests, I used the latest BIOS received although new versions will certainly be available in the days to come. Asus being very reactive on the update of its BIOS.
We will also propose you in the coming weeks several overclocking guides for your processor but also for your memory kit with this APEX model.
- Motherboard : ROG Maximus Z790 APEX (BIOS Beta 0031)
- Processor: Intel i9-13900K
- Memory : 32 GB Teamgroup Delta RGB 7200 MT/s CL34
- Graphics Card: MSI GT 710
- Cooling system : Optimus Foundation + 480 mm EK radiator
- SSD : Western Digital SN850 NVMe SSD M.2
- Power supply : be quiet! Dark Power PRO 12 1500w
- Operating system: Windows 11 64 bits
- Display: ROG PG27UQ
A quick tour through CPU-Z to make sure everything is in order before we start our tests. We notice that with this version 2.03.0, our i9-13900K is perfectly recognized as well as the DDR5 memory. Now that our configuration is ready, let’s see if the BIOS is correct for the frequencies of our i9-13900K.
[nextpage title=”The actual frequencies:”]
As with every new processor test, our first idea is to check if the announced frequencies are actually reached. To do this, we will use the Cinebench R23 benchmark. Two cases will be used: a single core bench and a second one in multi core. The idea is to be able to judge the frequency reached and thus, to compare with what was announced by Intel in its slides.
Remember that the Boost frequency in bench is different depending on the processor. Be careful, as Intel points out, when we talk about Max Turbo frequency, it is the maximum frequency that can be reached by one of the processor’s cores executing a single-core workload(mono-thread). This frequency varies according to several factors: the load, the cooling system and therefore the temperature of your processor. This is a notion to keep in mind. Here are the frequencies we should reach on a single core during our run under Cinebench R23.
First step, we leave everything in AUTO in the BIOS except the XMP profile that we load in order to have a frequency of 6000 MT/s in 30-38-38-96 for our memory kit. We don’t make any other changes in the BIOS.
Test with the i9-13900K :
Here we go with the strongest processor, the i9-13900K. As you can see, we opened several windows to check the frequency and the temperature. The options in our BIOS have been left in AUTO but we will talk about it again in the power consumption section because it has a significant impact on it.
In single core, we can see that the #4 core reaches a frequency of 5800 MHz which corresponds to what is announced by Intel. We can notice that the temperature of the two cores that alternate at 5.8 GHz have a temperature of 65/66 °C.
When the 24 cores of our i9-13900K are solicited, the frequency is fixed on the P-Core at 5.5 GHz and at 4.3 GHz on the E-Core. As for the temperature of the hottest P-Core, it is 87°C and on the E-Core 70°C. Let’s not forget that we are equipped with a custom cooling loop of 480 mm. So if you choose this processor, it will be at least a very powerful AIO of 280/360 mm.
[nextpage title=”CPU overclocking:”]
When you say new platform, you have to adapt to it, but since we are quite close to the Z690 chipset, we shouldn’t have too much difficulty. We will just have to take into account the new specificities of the processors in terms of frequencies.
Protocol:
Before starting, it is necessary to have one or more reference scores with our i9-13900K at stock frequencies , i.e., without having made any modification except having activated the XMP profile. It is also very important to have at hand a sheet that will allow you to note all the tests you will perform as well as the results or failures. Personally, I have hundreds of sheets of my tests on which I sometimes go back to know how the processor behaved on such motherboard or in such test conditions. My own little bible.
For H24 overclocking, it will of course be necessary to take more time to fine-tune the voltage in order to provide it with the minimum necessary, but also to adjust each core independently if you want to take advantage of the maximum performance.
Load-Line Calibration in BIOS:
In the case of Rocket Lake, even if Asus advises a Level 4 for overclocking, I opted for a Level 7 in order to have the least vdroop possible.
Basically, I want the voltage chosen to be as close as possible to the load voltage. In the tables below, you can see the selected voltage, the effective voltage in idle and finally in load . The readings are made with a multimeter at the PCB of the motherboard. It is very important to know the real voltage brought to the different components but especially to your processor.
Overclocking under watercooling in different steps:
As usual, I will start the tests by choosing, via the BIOS, a starting frequency applied on the 8 P-Cores of the i9-13900K. I chose a starting frequency of 5500 MHz with a multiplier of 55, a BCLK of 100, a voltage of 1.20 volt and a Level 7. All the other options are in AUTO. I already had the opportunity to test my i9-13900K and it is far from being a war lightning unfortunately.
The idea is then, in the OS, to test the stability on several runs of Cinebench R23 multithread . If it’s stable, I increase the frequency by 100 MHz while checking the stability again. If the benchmark crashes, I increase the voltage by 0.05 volt increments in order to regain a stability allowing to run the benchmark. The objective is to get a “quick” idea of the maximum benchmarkable frequency.
Here is what we obtained for the i9-13900K. As you can see, we were very quickly limited by the temperature and this despite a fairly low voltage.
Our best score is 42329 in Cinebench R23 but with temperatures that are between 85 and 88°C. Our copy is unfortunately not a gold processor and behaved well under LN2. I’m waiting for the 13900KS to arrive in order to try to get my hands on a goldprocessor.
[nextpage title=”Memory overclocking: “]
For memory overclocking, we of course kept our Teamgroup Delta RGB 7200 MT/s CL34 kit and its Hynix A-die chips. The idea is to choose the kit that we think has the best overclocking potential. And as you can see, we were not mistaken.
The choice of your DDR5 kit according to the memory chips :
As it was already the case for DDR4, if you want to clock your memory, some brands will have a better potential. Currently, the kits announced by the different brands benefit either from Micron chips or Hynix chips or Samsung chips.
The “key” voltages of DDR5 :
For memory overclocking, there are 5 key voltages. These are the voltages that will have an impact on the overclocking and therefore on the frequency rise or the tightening of the timings. These are the CPU System Agent Voltage (SA), the DRAM VVD Voltage, the DRAM VVDQ Voltage, the Memory Controller Voltage and the IVR Transmitter VVDQ Voltage. Here is where these voltages are located in the BIOS.
If your PMIC module is not locked, enabling “High DRAM Voltage Mode” will give you access to voltages up to 2 volts.
Let’s go for the overclocking of this DDR5 :
At first, we based ourselves on the 7600 MT/s profile present in the BIOS of our Z790 APEX. This one passes without any problem, so let’s go to 7800, 8000, 8200, … but where will it stop?
So this DDR5 overclocking? The least we can say is that we were not disappointed. Once again, thanks to the Asus team that works on its BIOS regularly and has allowed us to test eight different ones since we received the Maximus Z790 APEX. We were able to reach a frequency of 8450 MHz with aircooling and timings of 34-45-45-30. Until a few weeks ago, we would never have imagined that we could reach these frequencies in aircooling.
Of course, to do this, we had to push the voltages and especially the VDD to 1.66 volt and the VDDQ to 1.67 volt. It is a frequency used for bencher and not for a H24 use. But you should know that several brands should offer soon kits with an XMP at 8000 MT/s. We could probably make a stable profile at 8000 MT/s quite easily by relaxing the timings but that was not the objective here.
On the Geekbench 3.4.4 benchmark we were able to reach a memory score of 16172 points, a score that was unimaginable for us only a few weeks ago.
[nextpage title=”The last word:”]
That’s it, we’re done with this ROG Maximus Z790 APEX combined with the Rocket Lake i9-13900K processor. By the way, if you want to know the complete performance of these processors against the competition, our article dedicated to it is here.
Our impressions of this ROG Maximus Z790 APEX are excellent and it lived up to all its promises. We were eager to test it and see how it would perform after the first Z690 APEX’s flop. Fortunately, this Z790 APEX is based on the 2022 versions of the Z790 APEX so they should all perform well.
We find all the codes of the previous generations of APEX models with the numerous tools present on the PCB as well as the regular update of BIOS for overclockers . The presence of profiles is a real plus proposed by Asus. While we had already tested our i9-13900K on the Z690 APEX version under LN2, we are planning a second run but this time with the Z790.
The card is starting to be listed on with a price of $799 or 839 euros and even 799.90 euros on Amazon (not available yet on the US website). The price is high, even higher than the Z690 APEX. If you want to take full advantage of DDR5 overclocking or if you plan to switch to LN2, then this is the card you need and not another one!
We’ll also be bringing you a review of the ROG Strix Z790-A Gaming Wifi D4 very soon.
Feedback from our Discord community
As you know, our Discord is very active and especially on overclocking. Several of our members have rushed to buy this ROG Maximus Z790 APEX and their opinion is more mixed than ours. Some of the retail cards seem to have a “bend”. The PCB is slightly bent at the base and this seems to come from the VRM radiator. Once the VRM heatsink is properly replaced, it becomes almost invisible. Another point, and rightly so, is the fact that the legs of the components on the back of the motherboard are not cut. When the card is often handled, especially to isolate it, it is the fingertips that get hurt and on a card intended for overclocking, this is a real shame.
Some people have stability problems like our colleague from the Igorlabs site regarding memory overclocking. Let’s hope that these problems come from a bad series but we will remain attentive for the future. As we said, our copy seems to be a retail version and does not suffer from the “bent” nor from stability concerns. We can’t imagine Asus offering different cards to the press and for sale, which would be totally counterproductive for the brand. However, there seems to be an A01 and A02 version.
ROG Maximus Z790 APEX
We liked:
- A high-performance power stage
- The ability to use high capacity and high frequency memory
- LN2 mode for liquid nitrogen testing
- The presence of two BIOS
- A BIOS that continues to evolve with the addition of new functions (IMC memory)
- DDR5 profiles within the bios to clock the memory
- The “tools” inserted on the PCB to facilitate extreme overclocking
- The pleasant surprise of an automatic intelligent overclocking (AI Overclocking)
- The reactivity of Asus to offer new BIOS for overclockers
- The presence of two PS/2 slots for clockers under XP
- The presence of LGA-115x mounting holes !
- The Q-Release button to release your graphics card
- The nice bundle
We would have liked:
- Uncut components on the back of the PCB
- The price to be at least the same as the Z690 since the card is almost identical except for the color of the PCB
As we told you above, “If you want to take full advantage of DDR5 overclocking or if you’re planning to switch to LN2, then this is the card you need and not another one!”. This ROG Maximus Z790 APEX is finally fully matured in terms of its PCB but also and especially thanks to the great team behind the design and the BIOS patching doing a crazy job.
In short, it will certainly be one of the best if not the last favorite of this year 2022. A special thanks to ASUS who offers us since several years the opportunity to test this APEX series in preview!