As AMD is rolling out its next-generation Ryzen 7000-series 'Raphael' processors, die hard overclockers are already finding ways to cool down these CPUs and push them to the limit. As reported by ExtremeTech Legendary overclocker Roman 'der8auer' Hartung this week delidded AMD's 12-core Ryzen 9 7900X processor and discovered that direct-die cooling lowers chip temperature by approximately 20 degrees Celsius under heavy loads.
Lowering CPU temperature by about 20 degrees Celsius in Cinebench (a resource heavy benchmark) enabled der8auer to increase the clocks on all 12 cores to 5.50 GHz by increasing the voltage by 30 millivolts. Even at 5.50 GHz on all 12 cores, the CPU temperature was only 74.9 degrees Celsius, which means that the processor has quite some headroom for further overclocking.
Integrated heat spreaders (IHS) are there to protect a fragile CPU die (or dies) and ensure decent contact with a cooling system in normal conditions. But IHSs as well as their thermal interface materials (TIMs) that attach them to dies are not always ideal from a thermal conduction point of view. Removing IHS can lead to more efficient cooling and better overclocking results, if you are brave enough to attempt it. Delidding (removing the IHS) a CPU usually leads to 10 – 15 degrees Celsius temperature reduction. In case of Der8auer's AMD Ryzen 9 7900X, the temperature difference in Cinebench R20 was about 20 degrees Celsius, well beyond typical expectations. There are possible explanations for this.
First up, AMD's IHS for AM5 CPUs is extremely thick, perhaps in a bid to maintain compatibility with previous-generation (AM4) coolers. Secondly, Roman 'der8auer' Hartung used his own liquid metal thermal grease that is not yet available and which is supposed to outperform existing liquid metal-based pastes as well as solder that AMD uses for its CPUs. New thermal interface is not going to dramatically lower temperature by itself, but a combination of direct-die cooling and new thermal grease can bring surprising results.
Since AMD only started to sell its Ryzen 7000-series processors on September 27, there are no off-the-shelf tools to delid these CPUs (so the overclocker had to custom-make one), there are no custom frames to hold a cooling system (again, he had to invent his own), it is hard for an average enthusiast to replicate Hartung's experiment. Nonetheless, the numbers speak for themselves. Lowering temperature by 20 degrees Celsius and pushing all twelve cores to 5.50 GHz is a big deal. Hartung says that eventually the delidding tool as well as custom AM5 frame for delidded CPUs will be available from his website.