[Hardware] Hacksawing a Motherboard Helped Me Set a 12900K Overclocking Record

[Agent47]

 

Intel’s Alder Lake has retaken the performance crown from AMD, but in some cases, chip bowing issues have resulted in sub-par cooling. I took a hacksaw to a motherboard to help fix the issue, resulting in an extra 50 MHz of clock speed that put me over the top, winning a world record with the Core i9-12900K in Cinebench R23 at 6.95 GHz. 

It has been a couple of weeks now since we got the first wind about Intel’s Alder Lake chip bowing problems, which is the result of Intel’s Z690 socket hold-down mechanism (ILM) having issues that can cause the chips to bend. The dust has seemingly settled on this topic, as news cycles tend to do, and the YouTubers are already taking facepalm photos for the next outrage that they come across (we can only guess what it will be). But, I am not finished, and neither is famous overclocker and entrepreneur Der8auer.

Intel’s Z690 is here, and there will be refreshes (we already know the 12900KS is coming), and then Z790 will arrive and I’m almost certain we will see the same type of speed bumps. Therefore it is worth the time to investigate this as an extreme overclocker looking for an advantage to improve performance and to cover why I wouldn't recommend some of the mods you might have read about.
Intel has used a lever-action hold-down mechanism, known as an Independent Loading Mechanism (ILM), on LGA mainstream motherboards for seemingly ever. The single-sided dual-point-of-contact mechanism holds the chip snug in the socket, and it can even cause scratches that you see left behind on your heat spreader when you disengage the ILM to remove your CPU for the socket (that’s actually a good way to tell if a chip is used or not). 
Intel’s ILM is simple, has always done the job fairly well, and seems to hold up great over time. In fact, you could demonstrate the mechanism to a six-year-old, and after a couple of seconds, they would get the idea of how it works. I have an LGA775 motherboard that has had chips inserted and removed over a thousand times, and it's still just like new. So why are there issues now with the new LGA1700 sockets for Alder Lake?
I want to start by saying there is nothing technically wrong with the mechanism. Intel designs it and conducts numerous safety and reliability assessments during the design process. If you take a look at the socket blueprint and read the specs, it is mind-blowing — Intel specs a myriad of factors, including the required pin contact pressure and torque specifications for the screws. If anything, Intel’s socket designs tend to be over-engineered. 

As such, if you put a Core i9-12900K on a motherboard, it will perform to its rated specification, but overclockability is not guaranteed. Much like with tuning a car engine, I could produce 50 horsepower more by flashing the ECU in my car to increase the boost pressure. Does that mean my stock car is trash because the manufacturer did not give me that horsepower from the factory? No, it doesn't. It has the horsepower it is designed to have, much like a 12900K runs the frequency it's rated for. But due to human nature, I want to go faster, and we can, so let’s find a way to add more horsepower to Alder Lake CPUs.

Now, time to make some suggestions for improvements. This project started off with my frustration with the poor contact between the chip and my liquid nitrogen CPU container. Knowing that I had already flattened my CPU heat spreader by lapping it, which means I sanded the surface down to be completely flat, and that the bottom of my CPU container was also machined and lapped flat, I was confused why the thermal paste in the middle of the chip was so thick. 
Make no mistake, thermal paste can be the weakest link in the cooling system. Thermal paste is a gap filler, and while we want it as thin as possible, we also want enough that we have complete contact across the entire top of the chip. Here are six different Core i9-12900KFs that I binned, showing the possible variation from chip to chip. This is why extreme overlockers lap their CPU — we want the best possible contact with a very thin layer of paste.
The thick paste we see here robs me of precious extra CPU megahertz during extreme overclocking because it reduces cooling capabilities. However, after studying the CPU’s integrated heat spreader (IHS) more, you begin to notice that the top and bottom edges of the heat spreader are holding the cooler up like it's on stilts. In some cases, the edges are so high there isn’t even any thermal paste spread there, causing the IHS to scratch your cooler when you twist it off. 

I lapped my best CPU (see below) as I usually do, but it didn’t help my mounts look any better. The paste was still thick in the middle, and there wasn’t any paste on the top and bottom quadrants. How is this possible if I lapped the CPU and the cooler on calibrated flat glass?