Notable source Yuri Bubliy (screen name: 1usmus) has managed to extract the latest AMD Ryzen 7000 “Zen4” CPU and memory tuning options from the latest BIOS. As previously expected, the Zen 4 chip on 600 series motherboards will have several new tuning options on top of the existing ones, which could be seen as a teaser of the upcoming AM5 platform.
As the company revealed at its Computex event, AMD Ryzen 7000 CPUs based on the Zen 4 core architecture will offer both enthusiast (enthusiast) and mainstream (mainstream) overclocking capabilities. It looks like we now have an idea of what to expect from the platform itself. The full list of overclocking and tuning features includes.
● Active Memory Timing setup feature with Memory Target Speed setting.
● Maximum IF frequency – 3000MHz
● LCLK frequency control
● VDDIO voltage control: DIMM VDD and DIMM VDDQ
● VPP voltage control
● UCLK mode – no change
● PBO and curve optimizer – no change
● Timing for each channel: A, B, C, and D.
● Extreme Memory Profile (XMP/EXPO) runs in two modes: low latency and high bandwidth.
● Active OC Tuner has 2 settings: CPU Current Limit and CPU Temperature Limit.
● Asynchronous CPU/PCIe Clock
● CCX Clock Control, 4 CCX
● Host Clock
First, AMD Ryzen 7000 “Zen 4” CPUs will come with Active Memory Timing setting feature and Memory Target Speed setting. This appears to be part of the XMP/EXPO (Extended Overclocking Profile) for DDR5 memory. Users will be able to adjust the timings for each channel (A, B, C and D) and also select from a range of predefined clock/timing profiles in the motherboard BIOS. There are also options to adjust the VDDIO (DIMM CDD / DIMM VDDQ) and VPP voltages, but the main thing highlighted here is that the maximum Infinity Fabric speed will be 3000 MHz or 3.0 GHz.
Yuri also notes that there are memory multipliers in addition to frequency, so it looks like the DDR5 overclocking scenario on Zen 4 will be a big undertaking. Low latency and high bandwidth modes have already been mentioned, where low latency offers the best performance, while high bandwidth mode aims to take DDR5 overclocking to the next level.
Continuing with the tuning options, AMD Ryzen 7000 “Zen 4” desktop CPUs will also offer Active OC Tuner with both CPU current limit and CPU temperature limit settings. Users can also adjust the Async CPU/PCIe clock, host clock and CCX clock speed.
Note that the Zen 4 chip features a 4-core CCX (Core Complex design) arrangement, which is similar to the Zen 2 design, as Zen 3 dropped the CCX and moved 8 cores in a single CCD. Therefore, each Zen 4 CCD will hold two CCXs and there will be a total of two Zen 4 CCDs on flagship Ryzen 7000 desktop CPUs such as the AMD Ryzen 9 7950X. In addition to the main tuning options, there are some DDR5 memory specific settings that can be found in the BIOS, such as.
● Dram ODT impedance RTT_NOM_WR
● Dram ODT impedance RTT_NOM_RD
● Dram ODT impedance RTT_WR
● Dram ODT impedance RTT_PARK
● Dram ODT impedance DQS_RTT_PARK
● Processor ODT impedance
● Processor DQ drive strengths
● Dram DQ drive strengths
● Processor CK drive strengths
● Processor CA drive strengths
● Processor CS drive strengths
● DDR RAS (tab)
DDR Training Options (tab)
● DDR Data Eye (tab)
