Sony’s new PlayStation 5 Pro has quietly introduced a very interesting heatsink design change. Popular console repair YouTube channel TronicsFix discovered that the PS5 Pro heatsink isn’t glossy-smooth – it features a rectangular spiral surface detail.
TronicsFix postulates that the deliberately machined surface pattern was implemented to reduce the occurrence of dry spots and surface oxidation caused by liquid metal thermal interface material (TIM) migrating across the heatsink. He also reckons it slightly increases the contact surface area.
If you’ve ever tried to evenly spread liquid metal, you will probably be aware that the material likes to form pools. It is also much more susceptible to flowing where you don’t want it, compared to traditional pastes. Systems designed for liquid metal heatsinks will therefore use a seal or dam around the heatsink to make sure this electrically conductive substance can’t get out and contaminate or cause damage to other system components.
TronicsFix also thinks that the movement of liquid metal over time is exacerbated in PlayStation systems that are kept and used in their vertical orientation. We know Steve at Tronicsfix has repaired and tuned a considerable number of PS5s (and other consoles), so his observations probably aren’t far from the ground truth of the situation.
It is interesting to see Sony has implemented the rectangular spiral ‘grooves’ on the heatsink that interfaces with the AMD APU as in some ways it goes against conventional cooling wisdom. Extreme overclockers and tuning enthusiasts sometimes spend a lot of time ‘lapping’ the processor surface and making sure the heatsink is just as polished and flat - but liquid metal has shifted the goalposts. Sony must surely have A/B tested this new heatsink vs a mirror-smooth one and found it a worthwhile thermal design change to implement.
With the PS5 Pro's boost in processing power – the much beefier GPU in particular - we assume these heatsink ‘grooves’ are one of the changes made to keep the specter of thermal throttling at bay.
The PS5 Pro was officially unveiled in early September but only started to become available to consumers earlier this month. Enthusiast and expert teardowns are still uncovering the secrets of the new design, but we learned most of the technical details from lead architect Mark Cerny during a launch live stream.
