Overclocking on our Z790 APEX:
Choosing your DDR5 kit based on 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 various brands benefit either from Micron chips or Hynix chips or Samsung chips. The latter two brands will be the most interesting. Our GSKill Trident Z5 RGB 6400 MT/s CL32 kit is equipped with Hynix chips as you can see. But be careful, there are Hynix M-die chips, the first ones that came out, but especially today Hynix A-die chips that allow to go up in frequency more easily.
We can not totally make a generalization, but in most cases, the kits between 6000 and 6400 MT/s are in Hynix M-die and from 6600 MT/s, they are almost all Hynix A-die. As you can see, our kit is a model with M-die chips.
DDR5 “key” voltages:
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 of our ROG Maximus Z690/Z790 APEX.
Attention, depending on the type of memory chips (Micron, Hynix and Samsung), the balance between these different voltages is different. Don’t panic, we will come back to this in our guide on overclocking Alder Lake and DDR5. If your PMIC module is not locked, by activating ” High DRAM Voltage Mode “, you will have access to voltages up to 2 volts. Let’s go for the overclocking of this DDR5 from GSKill.
Step 1: change processor and motherboard
Why? Simply because the IMC(Integrated Memory Controller) of my 13900KS is much better than the one of my 12900K. Now integrated in the processor, the IMC allows a more direct and faster management of the RAM than when the memory controllers were on the motherboard. As with overclocking, there is a “lottery” and some processors benefit from a better IMC that allows them to handle higher memory frequencies. Since in overclocking we are going to increase the frequency, we might as well take the best CPU at this game.
We will also do a performance test with the XMP profile and our i9-13900KS on this APEX Z790 in order to have a basis for comparison for our overclocking results.
Step 2: Baseline scores on the APEX Z790
Let’s start with a baseline score. It is very important because it will allow us to judge the gain of our different modifications. When you need to fine-tune your overclocking, don’t modify several subtimings at the same time because you might not know which one is the problem if your configuration is not stable.
We have our two reference scores, we can start overclocking!
Step 3: 7400, 7600 and 7800 MT/s
Good news as our GSKill Trident Z5 RGB 6400 MT/s kit is very docile. For once we did not use the memory profiles available in our BIOS since they are less interesting than the basic XMP profile. Also beware, the overclocking settings of a Hynix M-die kit are not identical to those of a Hynix A-die kit.
We start calmly with a frequency of 7400 MT/s CL32 and timings and subtimings that have been optimized to improve performance. Concerning the voltages, we go from 1.40 to 1.60 volt.
As expected, the speed in Aida64 explodes as well as the memory score in Geekbench3 which goes from 11676 to 14666 points. We continue the rise in frequency with 7600 MT/s while keeping the same voltages.
It’s a rolling business with a memory score that passes the 15K mark. In order to pass the 7800 MT/s we will have to push our voltage to 1.65 volt.
Here too, it passes very easily in Geekbench3. The kit seems to have more under its belt and even if the 8000 MT/s CL32 is not stable, it would still take some work to reach it without too much difficulty, but we could already detect an excellent potential for GSKill kit.
