LGA 1700's asymmetrical socket design means that older AIO coolers could have trouble with Alder Lake thermals
After Igor's Lab reported that on major changes to LGA 1700's socket layout - including a rectangular heatspreader, WCCFTech undertook tests with multiple Alder Lake "compatible" AIO coolers to identify whether or not the new IHS design would lead to cooling issues with older coolers.
The Igor's Lab reported predicted that, due to the new rectangular IHS design, older AIO coolers with a rounded contact surface will miss large parts of the IHS, leading to significantly higher temps and worse performance.
In order to test this, WCCFTech tested out a number of popular but older high-end AIO coolers, including the Corsair H150i Pro, the Gigabyte AORUS Waterforce X360, and the ROG RYUJIN 360. What they found is that, even with an LGA 1700 mounting kit, none of these AIOs made full contact with the IHS, with the RYUJIN faring the worst.
While temps weren't measured, it's likely that older AIOs could cause overheating and lead to lower boost clocks. If you're buying an Alder Lake CPU, that means that, in addition to a new LGA 1700 motherboard, you might also have to spend on a new AIO cooler for optimal performance.
It's important to note here that, while Ryzen 5000 series parts like the 5950X deliver somewhat lower gaming performance than the new Alder Lake flagships, power consumption is as much as 100W lower, meaning you can likely get away with an air cooler or smaller AIO.
Check out the Intel Alder Lake i9 12900K here on Amazon.