Understanding Nanometers in CPU Lithography

Lithography in CPUs often confuses many due to the misconception that the nanometer value (nM) represents the actual height or size of the transistor. However, nM is actually a measure of the advanced process technology used to manufacture CPUs, specifically the length of the drain to source, which is also known as the gate length of individual MOSFETs (Metal-Oxide-Semiconductor Field-Effect Transistors).

What is Nanometer in the Context of CPUs?

Currently, the smallest achievable nM value for manufacturing CPUs is at 2 nanometers, with this value indicating how closely transistors can be packed on a chip. The lower the nM value, the more transistors can be accommodated on a single chip, resulting in more powerful and complex chips. Additionally, a decrease in the channel length of these transistors leads to a reduction in power dissipation, allowing for higher clock speeds with less heat generated.

Myth and Reality: Nanometer and Transistor Size

Another common misconception is that smaller nM values directly translate to smaller transistor sizes. This was true in the past, particularly when 3D transistors were introduced, and the nM was used to describe the gate length of the transistor. However, as technology has advanced, this relationship has shifted.

Modern nM values are more reflective of how a chip has been evolved from the previous generation rather than the size of the transistors themselves. Due to the lack of a standard industry meaning for nM, it has become more of a marketing term. The only meaningful information you can derive from nM is that the manufacturer has managed to pack more transistors on the chip and has found a way to improve the transistor density with higher tolerances.

Industry Insights via Comparison

To better understand this, let's consider a specific comparison. In one analysis, Intel's 14nm technology was compared to TSMC's 7nm technology used by AMD. Surprisingly, the actual transistor sizes were nearly the same in both technologies. The only observable difference was that transistors in the AMD CPU were slightly closer together, but not by the expected factor of two (as might be inferred from a reduction in nM value). This highlights that the nanometer values do not directly correlate with the density or the actual size of the transistors.

Conclusion

In summary, when it comes to CPU nanometer measurements, it's important to understand that these values represent the process technology used, not the size of the transistors. As a consumer or enthusiast, being aware of these nuances can help you make more informed decisions based on actual performance and features rather than just relying on marketing terms.

For a more detailed understanding and visual explanation, you can refer to this video.