Military Embedded Systems

3U vs 6U VPX: Understanding the differences and applications


May 31, 2023

Dan Taylor

Technology Editor

Military Embedded Systems

3U vs 6U VPX: Understanding the differences and applications

In the defense industry, the right choice of technology can be a game changer, affecting everything from mission readiness to the tactical capabilities of our armed forces. One critical choice that often faces defense contractors is the selection between different standards for embedded systems.

Among the most prominent of these are 3U and 6U VPX. The choice between these two standards can have significant ramifications for the size, power, and capability of a system. Here we will delve into the differences between 3U and 6U VPX, highlighting their respective advantages, use cases, and how to make an informed choice between the two for your next project.

Further reading:

3U VPX: Features and Benefits

The 3U VPX is a versatile standard, designed with compactness and efficiency in mind. Its technical features include a size of 100 x 160mm, making it lightweight and compact, perfect for systems where space is at a premium.

The major advantages of 3U VPX stem from its size. It is lightweight and space-saving, which is invaluable in a number of defense applications, particularly in the world of uncrewed systems and avionics, where every gram can count. It’s also often more than adequate for tasks that are not overly complex or demanding in terms of processing power.

Typical use cases for the 3U VPX in the defense industry are diverse. You can often find 3U VPX in small unmanned systems, such as drones, where the light weight and compact size are invaluable. They're also common in avionics, where they can handle the tasks of flight control and monitoring without eating up too much space. Portable communication systems, too, frequently leverage the benefits of 3U VPX.

6U VPX: Features and Benefits

The 6U VPX, in contrast to the 3U, offers greater power and capability, albeit at the cost of a larger size. It measures 233.35 x 160mm, providing more space for connectors, processing units, and other components.

The advantages of the 6U VPX lie in its increased capacity for higher-powered components and its increased number of connectors. This allows it to take on more complex and power-intensive tasks. If you need server-grade computing power in a rugged, military-standard package, the 6U VPX is a likely candidate.

6U VPX find their use in a variety of demanding applications in the defense sector. These include radar systems, where their higher processing power can handle the complex calculations necessary for radar operation. Electronic warfare systems also benefit from the 6U VPX, with their need for high-speed data processing and signal generation. Other use cases include any application where high-capacity, high-speed data processing is a must, or where there's enough room for a larger system.

Differences Between 3U and 6U VPX

Comparing 3U and 6U VPX, some clear differences emerge. The most obvious one is size, with 6U VPX being significantly larger than 3U. This extra size translates into more space for connectors and components, allowing for higher processing power and greater complexity in the tasks the system can handle.

However, the 3U VPX's smaller size and lighter weight give it an edge in applications where these factors are crucial. Its compactness makes it the preferred choice for systems that need to be portable or that must fit into smaller spaces, such as uncrewed systems or portable communications gear.

In terms of power, the 6U VPX typically has the upper hand, with its larger size and greater number of connectors allowing for more powerful processors and components. Nevertheless, the 3U VPX is perfectly capable of handling less power-intensive tasks with efficiency and reliability.

Real-World Case Studies: 3U and 6U VPX in Action

Let's take a look at some real-world applications where these two standards shine.

In the case of 3U VPX, consider a reconnaissance drone. These drones often require lightweight and compact systems to maximize their range and maneuverability. Here, the 3U VPX provides adequate processing power for flight control, sensor data processing, and communication, while keeping the weight and size within acceptable limits.

For the 6U VPX, consider a shipboard radar system. These systems need high processing power to handle complex radar signal processing and interpretation. The 6U VPX, with its greater power and capacity, is well-suited to these tasks. And as these systems are typically installed in environments where space and weight are less critical, the larger size of the 6U VPX is not a significant disadvantage.

VPX and SOSA: An Important Combination

As VPX standards continue to evolve, one development worth mentioning is the Sensor Open Systems Architecture (SOSA). SOSA is a technical standard aimed at designing modular, multi-vendor, open systems architectures in C4ISR (Command, Control, Communications, Computers, Intelligence, Surveillance, and Reconnaissance) systems.

This standard, built upon existing open architecture standards like VPX, contributes towards improving system interoperability, scalability, and upgradability, while reducing costs, risks, and time-to-field. It's particularly relevant in the defense industry, which is a main consumer of VPX technology. The introduction of SOSA could lead to further advancements in the way VPX is used within the industry.

Both the 3U and 6U VPX can benefit from the principles outlined in SOSA. For example, a SOSA-aligned 3U VPX could be employed in a drone's modular architecture, ensuring easy replacement or upgrade of modules while retaining the light weight and compact size advantages of the 3U VPX.

On the other hand, a 6U VPX aligning with SOSA could be used in a radar system, facilitating easy and cost-effective updates to its processing components as technology advances. The higher processing power and capacity of the 6U VPX would be augmented by the added interoperability and upgradeability provided by the SOSA approach.

Future Trends in VPX Standards

As technology advances, so too does the world of VPX standards. One significant trend is the increasing push towards higher data rates: as sensor technology improves and data processing demands increase, VPX systems are required to handle the ever-growing demands for data. The VITA 67.3 standard, for example, has expanded the RF capabilities of VPX systems, allowing for faster data transfer rates.

The focus on cooling solutions is also a growing trend in the VPX domain. As processing power increases, thermal management becomes a critical aspect of system design. New approaches to cooling, such as liquid cooling and heat pipe technology, are being explored to keep VPX systems within their thermal limits while maximizing performance.

Finally, the shift towards the use of artificial intelligence (AI) and machine learning (ML) in embedded systems is influencing VPX technology. VPX systems are being asked to support AI and ML workloads, which can require significant processing power. This is driving the development of VPX boards with more powerful processors and GPUs, as well as the creation of VPX standards that support these components.