When Intel launches Alder Lake later this year, it’ll also transition from the LGA1200 socket introduced with Comet Lake to a new socket, LGA1700. LGA1700 is a new socket with significantly more pins and it’s not the same shape as Intel’s previous LGA115x / LGA1200 sockets.
Igor’s Lab has published some details on the new socket, with drawings and diagrams that appear to be genuine. They show a slightly larger motherboard plate (78mm x 78mm, compared with 75mm x 75mm for current LGA1200), but the shape of the CPU itself is now decidedly rectangular.
The new CPU’s different shape could cause issues for anyone trying to reuse a CPU cooler. It’s entirely possible — even likely — that LGA1700 CPUs will have cores and hot spots in different physical places on the chip. Some heatsinks may not cover the entire CPU core effectively. This could also apply to AIO watercoolers. Those with smaller blocks may not cool the chip effectively, and the microchannels in the heatsink may not be in ideal places. Igor thinks Xeon and Threadripper coolers might work for this new setup because those sockets are more rectangular. It depends on what kind of conversion kits become available and which manufacturers support them.
Another wrinkle in the situation is z-height. LGA1200 supported z-heights of 7.312mm to 8.249mm. LGA1700 is thinner, with a z-height of 6.529 to 7.532mm. It’s not clear if the reduced Z-height is a consequence of Intel’s die shaving, which improves heat dissipation, or if the company was able to reduce socket height through other changes. Either way, the two standards only overlap at the very bottom and very top of their respective ranges.
Some conversion kits might be able to deal with this by changing the height of the base the cooler sits on, but this will depend on what kind of CPU cooler you have. Igor notes that heatsinks with heatpipes intended to directly contact the CPU could fare particularly poorly if Alder Lake’s hot spots are in different locations than Rocket Lake and previous CPUs.
We’re not preemptively declaring that no conversion kit will work. Companies such as Noctua have built a reputation for excellent hardware, and I actually don’t believe the company would release a conversion kit for a product if it couldn’t provide an acceptable experience. Don’t be surprised, however, if it turns out that a lot of high-end coolers for standard AMD and Intel CPUs today (as opposed to Threadripper and Xeon) can’t be easily adapted for Intel’s new platform. In this case, there may be good reason to opt for a new CPU, if you plan to upgrade when Alder Lake comes out.