Intel LGA-1851 Socket Adopts New “RL-ILM” Loading Mechanism, Better Thermals & Cooler Compatibility Detailed

Intel's LGA-1851 socket will be getting a new "optional" ILM configuration for better thermal performance without requiring a contact frame.

When we talk about Intel's history with CPU sockets, the firm is known to make frequent changes within each generation. Similarly, the upcoming LGA-1851 will feature plenty of changes, and the pin layout, as we already discussed earlier, has shown that the upcoming socket is completely different from the previous LGA 1700.

Now, hardware leaker Jaykihn reports that LGA-1851 will debut with two different loading mechanisms, with one being the traditional ILM solution which will be compatible with existing coolers, and the other being RL-ILM (Reduced Load ILM) which has been designed specifically to offer enhanced thermal performance but with different compatibility requirements.

LGA1851 will have two ILM types.

- Default ILM solution, which is similar to LGA1700’s. Is angled at 2 degrees.

- Reduced Load ILM (RL-ILM), which is flat and has an improved thermal performance. It is covered under Intel warranty and is optional for system vendors for <$1 per.

— Jaykihn (@jaykihn0) July 3, 2024

For those unaware, by loading mechanisms, we mean a metal structure that surrounds the socket and provides the mechanism for securing the CPU, seating it onto the motherboard. Up till now, Intel's CPUs debuted with a single mechanism called the ILM (Independent Loading Mechanism), but the ILMs were known to be disadvantageous for overclockers since the mechanism reduced the contact area of the processor with the cooling solution, ultimately causing troubles in heat dissipation.

Several contact and direct-die frames were implemented for previous 12th/13th/14th Gen CPUs to enhance the cooling capabilities of those chips as they ran quite hot, however, Intel has designed a dedicated RL-ILM to fix the issue.

It is said that the integration of RL-ILM (Reduced Load) is optional for vendors, and it comes with improved thermal performance as well. It will reportedly cost only $1 more than the default configuration, and it's expected that vendors who want to focus on high-end overclockers will integrate the mechanism.

Intel hasn't disclosed the design features yet, but we believe RL-ILM will enable a better contact area by spreading the contact area more evenly across the IHS, ensuring uniformity and, ultimately, a better cooling performance.

However, Jaykihn states that the Intel LGA 1851 RL-ILM configuration has a compatibility risk since the cooling heatsink would need to apply a minimum of 35lb of loading force to the processor. This means that consumers wouldn't be able to utilize coolers of their own choice but rather those compatible with the loading mechanism. Cooling manufacturers will also have to provide the proper info to users who wish to utilize the RL-ILM configuration for perfect compatibility.

This is something to consider, but since users who opt for the high-end overclocking route already have a decently equipped cooling solution, achieving the loading force wouldn't be much of an issue.

LGA1851 is shifted upwards by 0.8mm on the board compared to LGA1700. This serves no major significance for compatibility nor performance, but it’s worth noting.

I may cover hotspot location measurements for arrow lake (desktop and mobile) and lunar lake in the future.

— Jaykihn (@jaykihn0) July 3, 2024

Besides the ILM, the leaker also highlights some additional details of the Intel LGA 1851 socket which includes an upward shift of 0.8mm on the board compared to the LGA 1700 socket while the motherboard-to-IHS height has been increased slightly from the LGA 1700 socket too (6.831-7.497 mm vs 6.76-7.4mm). Intel's LGA 1851 socket will debut in October with the launch of the Z890 PCH motherboards for the next-gen Arrow Lake-S Desktop CPUs. The socket will also come to budget & mainstream offerings in early 2025 and will support future generations of Intel's CPUs such as the Panther Lake lineup.