ASUS ROG has started selling its RTX 4090 XG Mobile graphics card in China and Japan this week. Japanese customers are being charged a cool $3000 for the pint-sized powerhouse external GPU, and Chinese buyers are getting a slightly better deal at $2700. It should be noted that this eGPU is the ( GN21-X11 ) mobile variant of the GeForce RTX 4090, and not the full fat desktop version. The newly updated XG Mobile enclosure can only be connected to an ASUS Flow laptop, which limits the scope of compatibility to an already very expensive range of devices. The proprietary connection standard will keep customers in the ASUS ROG mobile hardware ecosystem - but higher end models can be configured to house a GeForce RTX 4070 mobile GPU, so the RTX 4090 XG Mobile seems to appeal to a very small buying niche.

The XG Mobile interface uses the PCIE Gen 3 x8 standard of connection, and the GPU has access to a dedicated 63 GB/s of bandwidth. This beats the Thunderbolt 4 standard of 40 Gb/s, by a 57% margin. The enclosure acts as a docking station - its features include an up to 2.5 Gbit Ethernet, a single HDMI 2.1 port, one DisplayPort 1.4 with G-Sync support and three USB 3.2 Gen 2 ports (3x Type-A + 1x Type-C). ASUS ROG has engineered the docking station/enclosure to be as compact as possible (21.7 cm x 16.5 cm x 3.26 cm), when compared to competing products from other manufacturers. The whole package weighs in at 1.3 kg, which will ensure decent portability for gamers on the move.