Ryzen 7000X3D overclocking for advanced users
SkatterBencher has a lengthy article and video on overclocking of the Ryzen 9 7950X3D, while der8auer spared no time in delidding the first Zen4 desktop CPU with 3D V-Cache.
Users will not find hidden motherboard menus to unlock “X GHz” settings for Ryzen 7000X3D. Those processors are officially locked for overclocking, at least in traditional way. To achieve the best performance out of the Ryzen 7950X3D, users must rely on technologies such as Precision Boost Overdrive 2 or EXPO (memory overclocking profiles), but those will not give the best results.
SkatterBencher goes into details explaining each of the possible strategies to unlock more performance out of Ryzen X3D CPUs. He explains the differences between two of Raphael dies (chiplets) in the new Ryzen 9 X3D package. This is where we learn that CCD0 (with 3D V-Cache) has a lower max frequency limit of 5250 MHz and lower voltage limit of 1.2V, while the CCD1 (without 3D V-Cache) can go higher up to 5750 MHz and 1.4V. For comparison, the original 7950X SKU has just one Fmax limit of 5850 MHz and 1.475 volts.
With PBO2 and voltage/frequency curve optimizer enabled, overclocker can force the CPU to achieve higher frequencies. This requires a lot of fine tuning, but this strategy can increase the Fmax frequency to 5900 MHz. This method involves lowering the V/F curve to force the CPU clock to go higher, but there is actually an even better method that makes use of ECLK feature available for Raphael CPUs.
SkatterBencher explains that Raphael ECLK (External Clock Generator) is available for Ryzen CPUs and how it can be used to push 7950X3D into higher clocks. In short, by changing ECLK to 105 MHz, a voltage-frequency-temperature point will increase from 5.0 GHz/1.1V/50°C to 5.25 GHz with the same voltage and temperature point.
The point is, Ryzen 7000X3D series can still be overclocked, but this requires ECLK and VF adjustments, which may be complicated to some users (SB has a step-by-step guide). Furthermore, the mileage will vary depending on cooling solution, motherboard use and of course the capacities of each Ryzen sample.
At stock, the CPU runs at 4255 MHz with all cores at 0.9V during Prime95 testing. The temperature reportedly is 66.8 °C while the full package consumes around 121.6W. By disabling AVX512 instructions, the clock speeds are increased to 4553 MHz, but this comes at a cost of higher temperature at 81.5 °C and power measured at 134.2W. With ECLK/PBO/VF overclocking, SkatterBencher reports 4592 MHz, 83.3 °C and 152.1 watts for AVX-512 disabled Prime95 workload (remember this is average frequency from all cores).
This overclocking brought up to 9% better performance in synthetic tests that were used. Unfortunately, it brought minimal performance improvement for gaming, as shown by this slide:
We may actually hear more about 7000X3D overclocking soon, as another known overclocker Der8auer had already delidded the first unit. Contrary to what the renders have shown, there is not much of a visual difference between both dies in real life photography.
Source: SkatterBencher overclocking (article, video), De8auer delidding