External GPUs have had a bit of a rocky existence over the last decade. Touted as the solution to gaming on the go, the idea that you could effectively share hardware between your powerful desktop at home and laptop on the go was a gamer's dream. The idea that you may no longer need to have both a laptop and a desktop PC, in addition to a GPU, was supposed to save everyone some money and, in theory, allow for more frequent GPU upgrades. There are other benefits as well. For example, there's no need to sync files between multiple computers, and the external GPU could effectively integrate as a third-party dock connecting your monitors, external hard drives, mouse, keyboard, and speakers over a single thunderbolt cable.

While some people loved their external GPU enclosures, they never quite took off as promised. There were teething problems early on, from requiring a reboot to connect, to poor performance and limitations on the number of devices that could be connected. More practical issues also arose - they were noisy and produced a lot of heat directly on your desk. Additionally, you needed a laptop which could support this setup, which limited your options during the first wave of Thunderbolt eGPUs. The docks themselves were also expensive, making a decent eGPU setup almost as costly as a decent laptop and dedicated PC GPU.

However, some time has passed, and eGPUs have quietly been making a comeback. There are a couple of reasons for this. The potential inflection point for their future progress is clearly Thunderbolt 5, a standard that promises to alleviate, if not eliminate, a decent chunk of the issues many users have experienced with eGPUs previously. So here, in no particular order, are the reasons why Thunderbolt 5 might be the catalyst eGPUs need to make a comeback.

3 Improved bandwidth

Doubling the available bandwidth will certainly help

This one is obvious: Thunderbolt 5 supports up to 80Gbps of bidirectional bandwidth, doubling that of 40Gbps with Thunderbolt 3 and 4. Previously, GPUs were forced to run on a reduced bandwidth, and little space was left over for things like external drives or high refresh rate/high-resolution monitors. External GPUs also suffer from a problem called "host display mirroring," where frames rendered back to the laptop monitor or display connected to the monitor must be returned to the host laptop before being displayed, creating a "round trip" that consumes bandwidth. This bandwidth limitation caused many issues with external GPUs, especially when playing at higher resolutions or using high-quality textures.

There's a lot of complexity to discuss here. Still, the important point is this: by doubling the theoretical bandwidth, more speed will be available to external graphics cards, allowing for better performance, more external devices, and potentially more options for external storage. We'll need to wait for some Thunderbolt 5 supported laptops to hit the market, but there's clear potential here to resolve many limiting factors for previous Thunderbolt 3/4 GPUs.

2 Massively improved power draw and delivery

Are you ready for 240W charging?

Another massive change with Thunderbolt 5 is a considerable increase in the supported power delivery. To support Thunderbolt 4, a laptop needed to support 100W charging via a Thunderbolt port, with a peak draw of up to 140W. Thunderbolt 5 is taking this further, increasing the available power budget to a whopping 240W minimum power draw and matching it with 240W power delivery. This means that not only will your laptop be able to charge faster over Thunderbolt 5, but it could also support directly powering things like external GPU enclosures from your laptop's power supply.

How practical this will be remains to be seen. It doesn't make much sense to me to have a massive laptop power brick with you at all times in order to avoid a single power cable into your static eGPU, but there's potential here. The improved charging speed is more than welcome and will make its way into laptops, but the power delivery is what's exciting. Maybe we'll see a class of low-power capable external GPU enclosures designed for lower-end GPUs. To me, if they're affordable, this could be a viable budget option for those looking to combine a laptop dock with the ability to do some light gaming/photo editing without going all out on an overkill gaming rig.

This could also be huge for handheld gaming devices like the Aya Kun, which can already be paired with an external enclosure to make them great desktop gaming machines. The increased charging speed means they could be charged up on your desk in an hour or less.

1 Efficiency improvements

New DisplayPort tweaks reduce bandwidth usage

This is a bit of a catch-all expansion on bandwidth improvements. Implementing the latest standards across the board (including for DisplayPort, USB, and PCI) makes a whole host of efficiency improvements available. This includes DisplayPort 2.1, which has a host of specific improvements designed for DisplayPort's transmission over USB, as well as a new USB data tunneling protocol (which is still just optional). The enhanced DisplayPort connection is not only more efficient but also expands on the existing DisplayPort standard to support up to three 4K 144Hz displays.

This DisplayPort expansion is driven by a new ability to reconfigure the connection to support a unidirectional bandwidth of up to 120Gbps. This enables extremely intensive video applications by allowing one of the four directional 'lanes' to effectively change its direction, allowing 40Gbps in one direction and 120Gbps in the other (as opposed to the 80Gbps bidirectional supported by default). The effect of this is that even the most intensive monitor configurations will be supported along a single cable.

Ultimately, these efficiency gains mean that more usable bandwidth will be available for GPUs and devices connected over Thunderbolt. The usable bandwidth figure can change per your use case, naturally. But the less overhead from the Thunderbolt protocols, the better, and the more performance we can enjoy with eGPUs.

Thunderbolt 5 is just on the horizon

We expect to see some Thunderbolt 5-equipped laptops shortly, and I am pretty excited. As a long-time user of a Thunderbolt 3 dock, I've always enjoyed the single-cable charging and monitor experience. Being able to sit down at your workstation with a laptop and get right into your work is great, and would only be improved by an eGPU setup. Hopefully, we're entering a bit of a "Goldilocks" era for eGPUs, where increased demand from handheld consoles, improved standards, more competition, and some time spent ironing out the quirks can bring us a generation of highly functional and reliable eGPU enclosures.