Contact pin optimization to improve signal at high clock speeds
New X870E motherboards for AMD processors and Z890 boards for the new Intel Core Ultra 200S processors are now coming to the market. There will be one new feature on Asus boards that is supposed to improve the performance of RAM. It’s a new DIMM slot design that may not look any different on the outside, but has improvements that should allow DDR5 to overclock to higher clock speeds with better signal quality for more stable operation.
Asus has named this innovation NitroPath and it is a special DIMM slot design. You probably know that the electrical communication of the processor with the RAM is very sensitive to interference and signal quality. It is probably the most sensitive part of the motherboard and the ability to achieve high memory speeds requires very good PCB design and manufacturing quality. For example, even the mere presence of four instead of two slots on the board is something that makes a difference. The NitroPath slots aim precisely to improve signal quality and get to higher memory clock speeds.
According to Asus, this improved design allows to increase the speed of the memory (when overclocked) by about 400 MT/s (400 MHz in the so-called effective clock speed), which means that the same DDR5 memory will be able to work reliably at a clock speed higher roughly by this value compared to a board with standard DIMM slots. According to Asus, the slots also hold the memory modules with more force (+57% better slot retention force, 20–25% stronger latches securing the memory in the slot). This should improve the service life of the slots when the modules are replaced frequently in a motherboard, although wear and tear on the slots is hopefully not a common problem in practice for most people.
Improved pin design
The reason the slots are supposed to (according to Asus anyway, it’s a question how well it works out in practice, of course) achieve better clock speeds is that they have reworked the pins that touch the contacts on a module. The idea was to shorten the stub of the pin that extends beyond the contact plate. The pins of DIMM slots don’t actually make contact with the contact plates with their tips. The pin is curved, making contact mid-length, with a relatively long “stub” continuing on from the contact spot.
However, this protruding stub of the pin has a negative effect. During high-speed communication of DDR5 memory, the electromagnetic signal travels to the dead-end part of the wire and is reflected from its end (and the stub might also probably work as an antenna emitting electromagnetic interference). This then degrades the overall signal clarity in the motherboard wiring between CPU and the modules and thus the ability to reliably transfer data.
NitroPath has these stubs significantly shortened (by up to 70%) due to the fact that they are bent downwards and do not need a second support in the top of the slot for keeping contact pressure. You can see this in the comparison cross-section diagram from Asus. This design reduces the interference, and because the signal quality is better, you can get better memory clock speeds with the same processor and the same modules before instability starts to occur (the memory becomes unstable at a higher clock speed than before).
The difference likely isn’t that would have some revolutionary impact and these slots probably won’t be something that other boards can’t compete without, but it’s a nice bonus. The NitroPath slots don’t require any special support from the CPU or DDR5 modules – any existing models can be plugged into them. So the use of NitroPath is completely transparent. Similarly designed slots are likely to appear later from other manufacturers. Asus has reportedly developed them in cooperation with the connector manufacturer Lotes and should have about a year-long exclusivity on them.
The first boards are already out
The first boards with the NitroPath slots are the Asus ROG Crosshair X870E Hero and Asus ROG Strix X870E-E Gaming Wi-Fi for Ryzen processors (on the AMD AM5 platform). However, the technology will also be available on boards for Intel processors, on the new LGA 1851 platform models for Intel Core Ultra 200S (Arrow Lake) CPUs. It will come on the Asus ROG Maximus Z890 Extreme, Asus ROG Maximus Z890 Hero and Asus ROG Strix Z890-E Gaming WiFi motherboards.
Asus will be using these NitroPath slots for boards with four DIMM slots, which generally have a poorer ability to achieve higher memory speeds than dedicated enthusiast boards with only two slots. This is because a second DIMM slot on the same channel “corrupts” the signal quality much like toset overextending pin stubs in the slot, even when not in use (and if the memory controller is really serving two modules per channel, that leads to reduction in achievable clock speeds occurs as well for other reasons). According to Asus, current dual-slot boards have such a good PCB design and CPU-memory communication traces that NitroPath technology would no longer have a similar effect with them, which is why its dual-slot boards don’t use those slots yet.
The CAMM2 standard would also help here
Maybe it’s worth mentioning one more thing. The problem addressed here concerns DIMM connectors, but should not occur with CAMM2 (or LPCAMM) memory with its compression-based contact. Their attachment mechanism may also eliminate the problem of that dead end wire stub, and in general this technology is also aimed at improving the signal quality between the CPU and the memory (fact that this standard does not facilitate using two modules per channel likely helps in itself).
Read more: CAMM2 memory modules for desktop are closer than it seemed
Thus, switching to CAMM2 memory instead of using DIMMs would also be a solution. CAMM2 could probably achieve even better overall signal quality than NitroPath’s DIMM slots, and if things were purely a matter of maximum performance, it’s probably a better solution. However, this would obviously require new modules that would not be compatible with regular boards using DIMMs, while Asus’ solution does not break memory compatibility with other existing board models (and that is obviously a significant plus in its favor).
Sources: Asus, Tom’s Hardware
English translation and edit by Jozef Dudáš
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