What is an eGPU?
Imagine a perfect world in which even the most thin and light notebook is as powerful as the most powerful desktop PCs. Manufacturers of mobile computers tend to make this dream a reality for many years, but currently it’s still impossible. Yes, with every new generation of laptops are getting faster, but the producers still have to compromise with the speed of the components for the sake of mobility and energy efficiency.
One possible solution to the «alignment of forces» between the desktop and laptop PCs is to install so-called external (external) graphics card which the laptop can easily compete with a desktop PC in terms of graphics performance. This idea revolves in the minds of high-tech companies for many years, but so far with mixed success. And although some of them already offer such solutions, they are still far from perfect.
What is an eGPU?
This acronym stands for External Graphics Processing Unit. In other words, the external video card. Generally, when you use this term, we are not talking about a specific graphics adapter, but rather on the appropriate external interface, compatible with a wide range of graphics cards that would allow them to connect to any laptop.
It is here that lies the problem that prevents the practical realization of this great idea. Modern graphics adapters using the interface bus, designed specifically for their particular needs – PCIe. It is able to provide transmission of data at breakneck speeds of up to 128 Gbps. Unfortunately, the most widely used standards for connecting peripheral devices (e.g. USB and FireWire) offer a route of transmission with much more modest capabilities. To design the interface based on them is not the problem, but the connection between the external adapter and laptop will be the bottleneck of such a system. In other words, the eGPU card is not able to develop their full potential and to provide graphics performance that is comparable or identical to a desktop computer.
For the concept of the eGPU there is good news. Interface technology in recent years, evolving at an impressive pace. First introduced in 2009, the technology Light Peak (now Thunderbolt) is already part of a large family of USB Type C and has the potential to eliminate the above-mentioned «bottleneck» when you connect the eGPU to the laptop. Although at the moment the latest version of the standard provides a maximum throughput of 40 Gbps (three times lower than the PCIe 3.0 x16), Thunderbolt is definitely a step in the right direction and has potential in the near future lead to the implementation of the yet unfulfilled dreams of many mobile gamers.
State eGPU in 2015
Having said that, you might decide that there are no real products eGPU does not exist. It really is so versatile eGPU still not available, but some companies – particularly those that spetsializiruyutsya on the development of gaming laptops, are already offering similar products for some of their models. Vivid (and recent) example is the family of Dell Alienware 15 and 17. Each of their representatives may be supplemented by a desktop graphics card thanks to a unique accessory Graphics Amplifier. Of course, we should note that its design engineers Dell cheated from the point of view of interface – instead of some popular methods for connecting computer peripherals (USB, Thunderbolt), they use a specially designed external PCIe 3.0 cable.
For this reason, the Graphics Amplifier can only be used with their own laptops. In addition, this accessory has several limitations – it cannot be installed graphics card longer than 10.5 inches and requires over 375 watts of power. In other words, if you want to connect to your laptop graphic monster GeForce GTX TITAN X / GTX 980 Ti or AMD Radeon Fury, you can’t do this, even with the help of this product as the Graphics Amplifier.
The prospect of universal eGPU solutions still seem remote, but every day it becomes more real. All necessary preconditions for this already exist. The integration of the new USB Type C / Thunderbolt in modern laptops is going according to plan and soon will not remain a mobile PC without the support of at least one such port. In parallel, Intel has not ceased to develop the standard within a relative short period of time the company has managed to double the transmission speed from 20 to 40 Gbps. His upcoming revision will offer even higher throughput, which will make Thunderbolt even closer to PCIe.
At the same time companies like Dell and MSI clearly doesn’t have intentions to abandon the idea of eGPU. MSI specifically showed some interesting prototypes of solutions like Graphics Amplifier, which in contrast is not yet for sale, but will probably appear on the market in the near future. Such products, of course, will still only compatible with laptops of certain companies, but the fact of their existence shows that the idea of eGPU alive and will continue to evolve. At least until, while mobile graphics chips do not reach the level of performance offered by desktop-class graphics cards.