The LGA1700 socket, which Intel introduced for the 12th generation of their Core CPUs last November, is known to have one or two problems with bending hardware. For context, I recommend our other two posts if you haven’t read them already. But in short, the problem is that the clamping force of the ILM (Integrated Loading Mechanism) is applied to the CPU in such small areas that, together with the shape of the CPU, this creates a leverage effect that bends the whole heatspreader, socket and often even the motherboard’s PCB. Consequently the performance of the installed cooler often suffers and the CPU runs quite a bit hotter than it would really have to.
Today we’ll look at two solutions to this problem, Thermal Grizzly’s 12th Gen Contact Frame and Alphacool’s Apex Backplate, and test them with various coolers against Intel’s stock socket and also our 1 mm “washermod” – credit to buildzoid again at this point. Two well-known waterblocks are used as coolers, the Alphacool Eisblock XPX Aurora with LGA1700 mounting adaption and the Corsair XC7 RGB Pro LGA1700, and additionally also the Corsair iCUE H150i RGB PRO XT 360 mm AIO.
Initial situation with cold plates in close-up
The ILM with its two relatively small contact points along the long sides of the LGA1700 CPUs effectively causes the center of the CPU to get bent downwards into the socket and thus lie shallower than the upper and lower edges. The resulting U-shape or concavity causes a greater distance to the cooler base and thus more distance that has to be bridged by the thermal paste, and this is exactly where cooling performance is lost.
If the CPU now bends away from the cooler base, a cooler base that is bent downwards in the same way would potentially already provide a remedy, which effectively follows the contour of the IHS and thus keeps the distance to be bridged for the thermal paste as small as possible. In fact, this is often the case with AIOs (pre-filled all-in-one water cooling systems), as seen here with the block pump unit of the Corsair H150i AIO. This is theoretically ideal for the almost equally curved Alder Lake CPUs without further modifications.
The Corsair XC7 RGB PRO LGA1700 has performed among the best of the dedicated waterblocks in our tests so far. One reason for this might be the compromise in the curvature of the base plate, which is much closer to a really flat surface. However, a slight convexity can still be found here, which, together with the high contact pressure ex-factory, can still keep good contact with most Alder Lake CPUs, as much as they make the bend.
The situation is different with the Alphacool XPX Aurora, which was not originally designed for LGA1700 and Alder Lake CPUs at all. Here, the base plate is almost completely flat and, strictly speaking, even concave if you consider the raised edges of the cold plate. This concept works best in theory, provided the CPU is also completely flat, as is usually the case with older Intel or AMD CPUs. However, as we already know, the Intel LGA1700 socket overturns this concept, which we will also see clearly in the tests.