Small Computers with PCIe Expansion Slots


The explosion of IoT devices and the shift of data processing from the cloud to the edge have produced new requirements for powerful and compact edge computers that are capable of performing complex tasks while maintaining their reliability, durability, and longevity amid harsh deployments at the edge. This is where computer manufactures introduce small industrial computers with PCIe expansion where they are powerful, expandable for specific feature upgrade, and ultra-rugged perfect for industrial deployments at the edge. Further in the blog, we will discuss PCI express slots and how they elevate the game for rugged mini PCs, especially for added benefits.

What is PCIe or PCI Express?


PCIe stands for peripheral component interconnect express, commonly abbreviated as PCI-e, PCIe, or PCI express which are all the same. PCI Express is a very popular standard for high-speed motherboard expansion bus interface that replaces other older standards such as PCI, PCI-X, and AGP. Compared to PCI that applies parallel communication, PCIe utilizes serial link connection architecture which leverages point-to-point topology. This makes PCIe more reliable, faster overall speed, and much cheaper to produce compared to PCI bus. Therefore, most motherboards and computers today are configured with PCI-e slots for expandability features.

Why PCIe Architecture is Important for Computing 

The Next Gen Rule


Currently, PCIe standard generations have already evolved from the first generation up to the sixth generation. The PCIe next-gen rule is basically explained PCI expresses exponential development in high-speed connection that doubles their connection speed for every new generation. The PCI-e bandwidth capacity for x16 link doubled from 8GB/s for Gen 1 up to 256GB/s for Gen 6 and their Giga transfer rate from 2.5GT/s up to 64GT/s for the latest Gen 6 architecture bit rate. However, current processors, computers, and motherboards mostly support PCIe Gen 3 architecture with newer applications requiring PCIe Gen 4 performance speeds.

The latest PCIe architecture innovation is much faster than current processors sold on the market, which creates a delay in the commercialization of hardware products with faster PCIe generation speeds.  This technology adoption model and its progression for mass deployment are normal because of the real-world application demands. PCIe gen 4 hardware products are becoming more prevalent at the time of this blog article, especially in high-performance computing in data centers.  

Learn More About PCIe 4.0 | Ultimate Guide


So, for the embedded computing market, it is best to choose mini-computers with PCIe slots that support PCIe 3.0 and later for their bus standard. Semiconductor manufacturers are constantly innovating to create ultra-fast processors to support Gen 4 speed for instance the AMD’s 3th GEN Ryzen 300 CPU, AMD X570 motherboards, and AMD Radeon™ RX 5000 Series graphics cards are capable of supporting PCIe 4.0.

Types of PCIe Sizes


PCI Express slots are available in different sizes that are described as x1, x4, x8, x16 which essentially state the number of lanes on the physical slot. A lane is constructed of two signaling pairs, each pair for receiving and transmitting data. Computers with PCIe 3.0 operate at an 8GT/s speed with a bandwidth ranging from 1GB/s for x1 up to 16GB/s for x16 lanes, resulting in 1GB/s for each additional lane. With the fast PCIe speeds, edge devices can upgrade powerful processors without the need to worry about bottlenecks from the bus connection.

Important notes for compatibility, PCIe cards are also backward compatible with different sizes and generations but with obvious performance sacrifices. PCI and mPCIe cards are not compatible with PCIe slots, mPCIe needs an adaptor to connect to PCIe slots.

What is Mini-PCie or mPCIe?


Small form factor computers with PCI express connection often configure their expansion slots with mPCIe. Mini PCI-express or mPCIe is a minimized-sized of PCIe interface that is specifically designed for more space-constrained devices. Mini PCIe is a perfect size for small PCs' expansion slot that allows the mini PCs to be deployed into narrow spaces and tight edges. The card size for mPCIe ranges from 30 x 50.95 mm for full-size and 30 x 26.8 mm for half-size cards. These types of cards have 52-pin edge connectors with two rows stag on a 0.8 mm height and with 1mm card thickness (without components).  Most small form factor computers use mini-PCIe expansion slots on-board in order to offer additional features for space-constrained edge computing solutions. The major benefit of the mini-PCIe is the standardization of the form factor; there are a variety of feature modules that can be added to the computer.

Learn More About Windows Single Board Computers | SBCs

PCIe Slots and Cards


The art of designing the smallest computer possible with a PCIe expansion slot for edge computing can produce a huge impact in terms of performance acceleration at the edge. With the help of performance accelerators that can be utilized thanks to the expandable (small form factor) SFF computers with PCIe slot, deployments at the edge now are capable to overcome the challenges for powerful solutions amid deployments in remote, harsh, and space-constrained environments. With PCIe slots, there are various performance accelerators and additional features can be configured for mini PC with PCIe features including the graphics card, sound card, RAID controller card, SSD, HDD, WIFI, Bluetooth, SIM card slots, additional I/Os, and much more. Therefore, designing compact edge solutions with PCIe expandability can create powerful focused solutions for industrial computing applications. For example, performance accelerator cards such as GPUs can be used for machine learning and inference analysis at the edge.

What Can You do with Additional PCIe Slots? 


Learn More About Performance Accelerators | GPU, ASICs, FPGAs, VPU, etc.

The future for smaller form factor computers with PCIe expansion slots is still growing rapidly from every aspect of the computing design.  Hardware accelerators are getting much smaller, powerful, and energy-efficient. Computer and motherboards are adopting the faster PCIe generation. Wireless connectivity is evolving at extreme speed with WiFi 6 and 5G connectivity at the edge advancing newer applications for artificial intelligence, machine learning, and deep learning models. All these factors are pushing forward the development of disruptive innovation at the edge.