As we already know, the AMD Ryzen Desktop CPUs feature three distinct clock speeds as a part of their internal memory structure, these include:
Infinity Fabric Clock (FCLK): Governs how quickly CPU cores can communicate across CPU dies and with SOC controllers (e.g. PCIe, SATA, USB) Memory Controller (UCLK): Governs how quickly the memory controller can ingest/exgest commands from RAM. Memory Clock (MCLK): The frequency of your main system memory.
This is to remain the case for AMD’s Ryzen 7000 “Zen 4” Desktop CPUs. One big change for the Zen 4 chips for consumer platforms will be the new EXPO technology which is also known as Extended Profiles For Overclocking and is a redone XMP design for the next-generation of AM5 CPUs. AMD’s technical representatives have already highlighted DDR5 memory overclocking to be a big deal on Raphael CPUs but at the same time, motherboard vendors aren’t allowed to talk about it till later this month. From what we have learned, it looks like AMD’s Ryzen 7000 Zen 4 CPUs will most definitely have DDR5-6000 as their sweet spot, allowing up to a 2:1:1 IFC ratio. A 1:1 ratio means that the memory is running with the same frequency as the memory controller on the processor and that should offer a best-case scenario. With Alder, Intel has broken down the memory ranks into two categories, a 2:1 mode known as Gear 2 which is the default for DDR5, and a 4:1 model known as Gear 4. The advantage that a 1:1 brings to the table is that it will allow for lower latencies and a balanced speed while a higher ratio will allow for better overclocking, & faster data transfer rates but will also lead to poor latencies.
AMD Ryzen 3000 “Zen 2” Sweet Spot - DDR4-3800 AMD Ryzen 5000 “Zen 3” Sweet Spot - DDR4-4000 AMD Ryzen 7000 “Zen 4” Sweet Spot - DDR5-6000
So DDR5-6000 for AMD Ryzen 7000 “Zen 4” CPUs already sounds great for AM5 and that will be DDR5-5600 by default. Higher frequency DIMMs are supported but as soon as you go above the DDR5-6000 limit, you will drop down to a 1:2 IFC. We are told that DDR5-6400 running at 1:2 will produce poor results and is not recommended if you are looking for better gaming performance. Furthermore, it also looks like X670E/X670, while designed for overclocking, won’t actually get the best memory overclocking motherboards as those are reserved for the B650E chipsets. Gigabyte confirmed that they will be offering the Tachyon with two DDR5 DIMM slots on a B650(E) chipset but we will have to wait sometime to see that motherboard in action. The X670E and X670 boards will support both overclocking and undervolting for Ryzen 7000 “Zen 4” CPUs but to what extent that is allowed purely depends on AMD. Now I did mention in the beginning that there’s a bad part to this news too. You see, AM4 has been around for almost 5 years and even now, there are several issues related to its AGESA firmware on various motherboards. We also saw that DDR4 memory support wasn’t as swift in the beginning & many revisions had to be made before the platform entered a stable state. The same is going to be the case with AM5 as it is a fresh start with DDR5 memory and also AMD’s first platform using the newer memory standard. We are told that with AM5, AMD is shipping a brand new firmware which starts at 1001/1002 (the current internal version is 1002, the original version was 0070 from January 2022). There’s still a lot of work that needs to be made and while we will get a stable platform at the launch next month, there will still be compatibility issues and such that users might face. Overall, Ryzen 7000 CPUs are looking to offer better efficiency than Intel’s Raptor Lake CPUs which are going all out to achieve the required performance to tackle Zen 4 parts. Both lineups are launching this fall so stay tuned for more information.
