RTX 4090 is put into an external graphics card dock for use: performance loss of 20%

Over the past few years, with the popularity of Thunderbolt 3 on laptops, external graphics docks have grown a lot. Although for hardcore gamers, this approach is not popular, it is a good solution for content creators who need to carry ultra-thin laptops on the go, occasionally experience gaming fun, or need discrete graphics cards to improve productivity.
There are also solutions such as Express Cards, M.2, and mini PCIe on the market, but overall, the efficiency and ease of use are not as good as the Thunderbolt interface. Constrained by the bandwidth of the interface, if the discrete graphics card is put into the graphics card expansion station to run, the performance will definitely be lost, and the range of the graphics card must be different in different application scenarios. Recently, a player has used the Asus Zenbook 14X Space Edition laptop equipped with an Intel Core i9-12900H processor, plus Razer Core X put in Nvidia GeForce RTX 4090 Founders Edition graphics card and tested the performance.

The test results of 3DMark show that when used as an eGPU, the GeForce RTX 4090 Founders Edition graphics card will have an average performance loss of about 20% which is not a small drop, bringing it down close to the GeForce RTX 4080’s level.

The bigger problem with this approach is the cost. Whether it is a graphics card, a docking station, or a high-end thin, and light laptop with good performance, the price is not cheap. At present, there is no graphics card expansion station with Thunderbolt 4 interface on the market.