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Sonnet eGFX Breakaway Box
Computer Reviews

Sonnet eGFX Breakaway Box

The power of Thunderbolt promises discrete graphical power for compatible ultrabooks; a small step in a niche direction.

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The concept of an external graphics card (eGFX) that promises to extend the life – and power – of previously non-upgradable computers has long been the dream of many laptop users. 2017 finally saw a handful of decent choices for traveling gamers and workflow professionals alike, with much of the credit due to Thunderbolt 3 finally freed from Apple machines. With speeds up to 40Gbps of bandwidth – the equivalent of four PCIe 3.0 lanes — Intel’s interface had a lot unrealized potential until now.

Sonnet’s eGFX Breakaway Box is just one of the few options available that promises to turn compatible systems into viable gaming machines or powerful workstations. The idea is a plug-and-play GPU solution that can perform like a desktop, whether it’s better graphics, higher frame rates, or productivity demands will appeal to specific users. All of that is possible through this discrete little box.

For those not interested in building a separate PC or buying a bulkier gaming laptop, the Breakaway Box makes enough sense. Sonnet is better known for workstation/server storage solutions so the look of this enclosure is functional rather than flashy, a basic steel chassis with a removable cover that features ventilated panels on the sides. Open it up and a simple layout continues with an OEM power supply (Akasa AK-PS035AF01) with a 24-pin ATX, 120mm fan, and a single PCIe slot making up the inside. A 1.5 ft (0.4m) Thunderbolt 3 cable is included.

The only bit of flair on this case is the “S” logo that lights up blue on the front, and if you can remember the days of Geocities and classic Shuttle PCs then you have a good picture of how small it actually is. It’s also worth noting that the Breakaway Box doesn’t feature additional Ethernet or USB ports, Sonnet explained to me that they wanted to avoid any stability issues with supplemental peripherals also plugged into the box.

In order to properly use the Breakaway Box there must be a direct link to the host computer via a Thunderbolt port for full bandwidth, otherwise it won’t power on at all through daisy-chaining. You probably knew that already but you do get some benefits as it has its own power supply that can charge laptops of up to 15W of power. This will be enough juice to breathe life into Macbooks and most Ultrabooks in just a few hours. It also runs whisper quiet with the fan whirling at 10dB no matter the card nestled inside.

What value you’ll get out of the Breakaway Box will largely depend on the graphics card you bring to the table. Theoretically, you could pair it with something magnificent like a Radeon VEGA FE, TITAN Xp or even a NVIDIA Quadro GP100 and have a standalone setup that spanks most gaming desktops into submission. However, the reality is that you’re most likely bringing something more affordable to spice up a humdrum laptop; albeit prospects with this type of combo are still good before the technicalities set in.

My testing included two distinct machines and three graphics cards that loosely represent entry-level (AMD RX 580), mainstream (EVGA Superclocked GTX 1070), and high-end (GeForce GTX 1080 Ti) categories. My laptop of choice was a configurable Toshiba Tecra X40-D, a lightweight workstation with an Intel Core i5-7300U and 8GBs of DDR4-2133 memory. My second system is a hand-built desktop equipped with an Intel Core i7-6700HQ, 16GB dual-channel DDR4-3200 memory, and a Gigabyte Z170X-Gaming 7 ATX motherboard. The latter option is important because we can compare onboard versus remote eGFX performance.

It’s not an exact science. I’ll just state right off the bat that if you adopt the Breakaway Box you can expect an almost desktop-like gaming experience on your laptop, before bothering to calculate performance drops. On that basis, the Breakaway Box did exactly what we wanted for heavy-hitting games like Forza Horizon 3, Grand Theft Auto V, Doom, and Battlefield 1. On the AMD 580 and GTX 1070 specifically, we did observe dips in frame rates by an average of 5-7fps and a maximum of 16-23fps in worst case scenarios. Regardless, I was surprised by how well the eGFX ran in tandem with a business-grade laptop. It obviously wasn’t perfect but we reckon the Breakaway Box should provide an adequate bump upwards.

However, we weren’t expecting miracles since Sonnet cautioned us to anticipate a 30% average benchmark decrease over Thunderbolt. In a purely technical sense, the RX 580 barely made the grade in 1440p/60fps where it sacrificed only 13% of its efficiency, while both NVIDIA cards have more raw horsepower to at least break even on diminishing returns. It was readily apparent that a card like the GTX 1070 fared better running games above 1440p/60fps, but at times had to give up 25% of its own power to do so. 4K gaming was still possible but came at the price of changing all settings to ‘high’ or ‘medium’.

Unfortunately, due to that bandwidth ceiling (40Gbps ~5,000MB/s over TB3 versus 126.08Gbps~15,760MB/s on 16X PCIe 3.0) the performance loss was unavoidable – equivalent to 3940MB/s. The GTX 1080 Ti is the biggest victim here, in some instances wasting as much as 54% of its potential just by utilizing Thunderbolt. Many will tolerate parasitic GPU drains experienced with cheaper cards and is a more logical match for eGFX — anything better flattly negates almost all that money spent for the privilege.

That’s the biggest issue not only with the Breakaway Box but all eGFX options currently available. Of course there are going to be performance losses, but we couldn’t believe how substantial they were with high-grade cards. This also comes with the advent of GTX 1050 Ti, GTX 1060, and RX Vega discrete counterparts are making their way into mainstream laptops. The Breakaway Box won’t seem like a value, but a niche product that requires a sizable investment.

I’ve waited a long time for external graphic card enclosures to hit their stride, and Sonnet’s eGFX Breakaway Box generally fulfills most of its ambitions to transform compatible laptops into something greater. For many, this may be their best chance at actually doing the impossible – as long as the inherent limitations of Thunderbolt connectivity are understood. Nevertheless, external graphics cards are gradually carving out a place for themselves, making Sonnet’s little box a promising alternative.

About the Author: Herman Exum