Let’s start with what will be the most complicated. This is a new platform that we are not quite used to yet regarding memory overclocking. But let’s start with a theoretical reminder since there are changes with the arrival of the ZEN 4 architecture as far as memory is concerned. While for the Ryzen 5000, the standard was to keep a 1:1:1 ratio between mclk:uclk:fclk, this will change with the Ryzen 7000. Indeed, they adopt the DDR5 memory. This one sees its frequency increasing, which implies changes in these ratios. AMD now recommends for AM5 motherboards in DDR5 a 1:1 ratio for the mclk:uclk and to finally leave the fclk in AUTO which will automatically set it to 2000 MHz. Theoretically, this is how it will behave:
- DDR5-4800 will give with the new ratios 2400:2400:2000 MHz (mclk:uclk:fclk)
- DDR5-5200 will give with the new ratios 2600:2600:2000 MHz (mclk:uclk:fclk)
- DDR5-6000 will give with the new ratios 3000:3000:2000 MHz (mclk:uclk:fclk)
Well, it may seem a bit complicated like that, but we’ll explain it all to you. First of all, don’t panic, if you activate your XMP or EXPO profile in the BIOS, everything will be set up automatically. The explanations we give you here are for those who want to overclock their memory kit.
fclk, mclk, uclk, a little reminder:
The fclk is the frequency of theInfiny Fabric which can be, since the previous generation, controlled independently via the BIOS parameters. By default, this value is set to AUTO mode and it is the motherboard that will manage its frequency to ensure the stability of the system. Its maximum frequency is around 2100/2200 MHz but it also depends on the quality of your processor, but that’s the lottery that will decide. The mclk also sometimes called ” memclk ” is the frequency of your memory kit and the uclk is the frequency of the memory controller.
You should also know that if you exceed the frequency of 6000 MT/s with your memory kit, automatically the frequency of the memory controller (uclk) will switch to a ratio of 1:2 always in order to ensure system stability. AMD indicates that the best performing frequency and ratios are 3000:3000:2000(mclk:uclk:fclk).
This AORUS X670E Xtreme does not have memory profiles in the BIOS, which is a pity, because it can be a good basis for work. However, AORUS has provided two very interesting and important options: ” Low Latency Support ” and ” XMP/EXPO High Bandwith Support “. Depending on your memory kit, the motherboard will optimize the subtimings.
Okay, but does this option have an influence on the performance? That’s what we will test immediately! We have done some tests under AIDA64 version 6.75.6134 beta and Geekbench 3.4.4 to highlight the increase of the memory score.
We then continued our overclocking by raising the VDD/VDDQ voltages to 1.45 volts in order to push the frequency of our memory kit to 6400 MT/s. Finally, we also pushed the FCLK frequency up to 2200 MHz in order to judge the gains. The most stable FCLK was at 2133 MHz.
And here are two captures of the performance obtained with these frequencies under AIDA64 and Geekbench 3.4.4.
Now that we have tamed the memory, let’s move on to the Ryzen 9 7950X processor which we will overclock while combining it with the memory overclocking.