Powerful embedded PCs that use the latest Intel or AMD chips are useful, but also unnecessary for many applications. There are many specialized tasks that do not require that kind of power, but rather a more efficient system, both in terms of the cost and operating energy.  

Once this need was met by ASIC systems, containing hardware specially designed for a single purpose. But scaling up ASICs is hard, as they are too hyperspecialized and cannot be repurposed into different tasks on demand. Nowadays, the best option for efficient embedded computers is an FPGA or an SoC. Let’s discuss what these mean and how they differ in detail. 

FPGA: The Successor to ASICs 

At the heart of any chip is the integrated circuit. This is the basic building block of computer circuits, with multiple ICs combined in various ways to create logic gates, which are then combined in turn to create complex processors. 

The CPU used in a normal computer is designed as a general-purpose processor, capable of handling a variety of requests. But it is also possible to fabricate a processor with a specialized function, requiring fewer logic gates, cutting down the cost of production and the power it requires. This is exactly what an ASIC, or Application Specific Integrated Circuit, is. 

The problem is that fabricating hundreds of chips for a single purpose can be a bad investment, because no changes can be made once manufactured. This also means that new chips need to be designed and manufactured for every single use case, which introduces another difficulty. Field Programmable Gate Array, or FPGA, was conceptualized to solve this problem. 

FPGA is simply a chip fabricated with plenty of logic gates and memory blocks, but without a pre-set architecture. Instead, you can set the configuration for the chip using a low-level Hardware Description Language (HDL), making it customizable for any type of application. This means FPGAs are easier to mass produce, as they can be turned into the specific chips for any task. 

SoC: The Complete Package 

A standard computing board is assembled from various components. The CPU needs to be paired with memory, a GPU, and networking functionality. Sometimes these features are part of the motherboard, while other times they require dedicated components, driving up the cost and complexity of the board.  

System on Chip or SoC is a type of integrated circuit that combines a processor with all the components it needs on a single chip. This means the CPU, GPU, I/O, storage controller, network controller – everything is fabricated on one chip. 

Not only does this make the resultant system more efficient, it also makes it more inexpensive. The existence of all the components that need to communicate on the same chip means that the system just needs to connect with storage and memory to be a completely functioning computer.  

SoCs are thus used in embedded and mobile systems to give quickly deployable boards that use very little power and are not held back by any performance limitations. 

So, Which One is Better? 

On a cursory glance, FPGA and SoC might seem like similar things, but they fulfill very different roles. An FPGA with a processor can handle highly specialized tasks, including a variety of interfaces for industrial processes. An SoC, on the other hand, provides great power efficiency, ideal for small systems that need to have low maintenance overhead. 

A boards like the LV-6717, for example, is a small form factor board that comes with an FPGA + processor design, giving you a fully programmable digital interface along with the power of an Intel chip. The result is a powerful industrial computer that can fit in many scenarios. 

Then there is something like the IB2-281, using an efficient Intel N processor to drive an SoC configuration. It packs a range of interfaces, including network ports like LAN in this one tiny board, along with a fully featured computer that can handle most tasks. 

The first is better for automation or HMI applications, while the second is best for IoT and other such scalable deployments. This means both FPGA and SoC have a role to play for different types of embedded computers.