AMD has been secretly working on photonics technology. Although this is an expected development (photonics is one of the emerging technology areas of both classical and quantum computing systems), it represents a new place for the company itself.
Information comes from recently published patents, AMD first filed in the United States in 2020. In this patent, the company describes a system that allows photonics-based communication systems to connect directly to the chip.
Because photonics utilize the speed of light, it significantly increases the speed of information transmission and improves energy efficiency (because the electrical resistance from ordinary media such as copper is not lost). AMD’s efforts to link rays directly to the die improve latency and power consumption, improving both performance and scalability.
Like most patents, this patent is ambiguous. In general, it describes the manufacturing steps required to make a chip that can handle photonic-based inputs and outputs. The manufacture of such chips is necessarily different from what the company currently manufactures, requiring the integration of both photonic chips and silicon chips on top of the organic redistribution layer (ORDL).
With the current approach These layers lack the organic part (O of RDL), usually a metal-based interconnect, redistributes I / O access to different parts of the chip. It differs from TSMC’s Through Silicon Via (TSV) technology, which enables integration of 2D and 3D chips. Therefore, we see an approach similar to the use of organic materials in OLED TVs and monitors. In that case, they are used to emit light depending on the electrical frequency they are exposed to.
Next, a typical SoC (System-on-Chip) is added on top of this organic layer to allow it to receive redistributed optical pulses that move information in and out of the chip itself. The SoC computes the information and passes it through the organic layer itself to the (horizontally placed) photonic chip. This photonic chip sends information where it is needed via fiber optic cable. AMD’s patent also simplifies the manufacturing process by allowing all three components to be manufactured on their own wafer substrate, later packaged together.
AMD’s patents show that the company is looking for ways to improve scalability beyond what is possible with traditional semiconductors. In recent years, the benefits of higher transistor densities have diminished, and computing requirements have only increased, so chip designers are a more creative way to improve performance and, crucially, power efficiency. I had to start looking for.
Not to mention the PC hardware store next door, these technologies are unlikely to become commercial products anytime soon. However, technology has a way to reduce the cost scale. The first hybrid applications of photonics and traditional SoCs can be years ahead, but such chip design space is essential for further scaling in costly high performance computing (HPC) environments.
The latter is also reaching its limits on the air-cooling capacity of increasingly dense, energy-efficient, and ultimately power-intensive chips. We are also looking for non-conceptual ideas for improving scaling. Immersion cooling, etc. The ability of photonics to transmit information without heating these systems seems like a safeguard while improving communication speed and energy efficiency.
