What is an external graphics processing unit (eGPU)?

Other approaches exist for attaching eGPUs, but they have limitations. For example, eGPU adapters that include Thunderbolt docking stations, such as those sold by Sonnet Technologies, allow consumers to upgrade the graphics capabilities of older devices, but the device itself would need to be replaced with a another with similar capabilities to take advantage of next-gen graphics. .

And while DIY approaches exist – it’s not uncommon in enthusiast communities such as eGPU.io to connect a GPU through an m.2 expansion slot traditionally used for a high-speed NVM Express SSD – they often cannot access the same level of bandwidth as a full eGPU.

How do they work?

While many modern computers do not have PCIe slots – a common interconnect method for expansion cards in desktop computers – they can still access the bandwidth reserved for these slots on modern CPUs by d other high-bandwidth means.

Part of what enables this is the improved speed of modern connection technologies. For example, Thunderbolt is capable of 40 gigabits per second of throughput; The m.2 drives are also on the PCIe bus and are capable of speeds of up to 5,000 megabytes per second, which is equivalent to Thunderbolt’s theoretical maximum of 40 Gbps.

For most users, it’s not realistic to use an m.2 drive to plug in external components, as it would leave a mess of wires on the desk and require a power source. But an eGPU enclosure is a practical solution, as it makes the process of connecting parallel processing capabilities as easy as connecting a Thunderbolt or USB4 cable.

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What are the advantages and disadvantages of an external GPU?

The main advantages of an eGPU are portability and expandability, allowing users who only need a high-end GPU for certain tasks (rendering video, for example) to put the device aside when is not used. Additionally, eGPUs provide a way to improve the performance of computing devices that may not be the latest and greatest, which can come in handy when working with a laptop that isn’t designed to be upgraded.

eGPUs have some drawbacks, usually technical in nature. Most importantly, users don’t get the full benefit of PCIe bandwidth, which means they’re likely leaving performance on the table compared to a desktop GPU implementation.

“It depends on the make and model of the host laptop, but you typically see 10% less performance through the eGPU,” Chen says. “For most people, that’s good enough, if you’re not looking to push the maximum number of frames and completely increase your quality settings.”

Chen notes that while the most recent version of Thunderbolt – Thunderbolt 4 – focuses on standardization and compatibility rather than speed upgrades, future versions will likely work to improve performance.

“Everything that happens after that, I think, will be bandwidth improvements because that’s where things are right now,” he says.

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Another downside: As post-production information site RedShark notes, how the screen is connected to the computer can affect performance. An internal display, like the one one has on a laptop, can be difficult to implement and can cost performance, as it requires Thunderbolt data to make a full trip from the eGPU to the machine, which must then render the result through the machine’s frame buffer. With that in mind, if you decide to go with an eGPU, you might want to consider using an external monitor to get the full performance of the technology.

Finally, one thing to keep in mind when buying an external graphics enclosure is that GPUs have increased in size and power consumption, which means that if the GPU enclosure you are using does not support supports the specific power rate or dimensions your card needs, it might not work. with the latest technology.

What types of machines can use eGPUs?

Today’s eGPUs are most often used with Intel-based machines, such as the small Next Unit of Computing (NUC) machines and other Intel laptops.

Laptops with AMD processors have traditionally been unable to use these devices. However, the USB4 specification, based on Thunderbolt 3, is available to all manufacturers, which would allow some AMD models to use the technology, expanding the potential eGPU user base.

While the PC market, whether Microsoft Windows or Linux, has been quick to adopt eGPUs, Apple’s move to its own silicon-based processors has made the devices less relevant to Mac users. , as Apple chose not to support external GPUs. However, older Intel-based Mac models can support AMD-made eGPUs, making this an option when considering an upgrade.