# ASUS ROG XG Mobile GC31 — External GPU Dock for Gaming Laptops > ASUS ROG XG Mobile GC31 ブラック 【日本正規代理店品】GC31S-026 summary. ASUS ROG XG Mobile GC31S-026 is a proprietary eGPU dock for select ROG laptops. Features RTX 3080 (16GB), 150W graphics, 100W PD, DisplayPort/HDMI, USB 3.2×4, SD Tags: graphics_card, asus, rog, xg-mobile, egpu, rtx-3080 Source: https://www.amazon.co.jp/dp/B08XTGJK8L Article page: https://web-autoai.com/articles/asus-rog-xg-mobile-gc31-gc31s-026?lang=en Prices and ratings change over time — check the article page for the current values. --- This article covers ASUS ROG XG Mobile GC31 ブラック 【日本正規代理店品】GC31S-026. ## Overview The ASUS ROG XG Mobile GC31S-026 is an external GPU dock designed exclusively for select ASUS ROG laptops that feature the proprietary XG Connector interface. It packs an NVIDIA GeForce RTX 3080 GPU with 16GB of GDDR6 memory, pushing up to 150W of graphics power. The unit measures just 208mm wide by 155mm deep by 29.6mm thick and weighs about 1.0kg, making it remarkably compact for an eGPU enclosure with a built-in PSU. On the connectivity side, you get one DisplayPort 1.4 and one HDMI 2.1 output (capable of driving up to 7,680×4,320 resolution), four USB 3.2 Gen1 Type-A ports, a Gigabit Ethernet jack, and an SD card reader. The dock also provides up to 100W (20V/5A) of power delivery to the connected laptop, so you can charge your notebook through the same cable. In the market, this is a high-end mobile GPU expansion solution. Unlike Thunderbolt-based eGPUs, the XG Connector offers a dedicated PCIe 3.0 x8 link (twice the bandwidth of Thunderbolt 4), reducing performance overhead and delivering desktop-like graphics performance in a portable form factor—provided you have a compatible ASUS ROG laptop. ## Compatibility Guide The XG Mobile is not a universal eGPU. It only works with ASUS ROG notebooks that have an XG Connector port—typically found on models like the ROG Flow Z13, ROG Flow X13, and some ROG Zephyrus Duo variants. Always verify your laptop's compatibility before purchase. * Interface: ASUS proprietary XG Connector (cable included) * Power: Built-in PSU, 100-240V AC input * External displays: DP 1.4 ×1, HDMI 2.1 ×1 * USB: 4× USB 3.2 Gen1 Type-A * LAN: RJ45 Gigabit Ethernet * Card reader: SD / SDHC / SDXC * Laptop charging: up to 100W PD via same cable Compatibility caveats: BIOS and driver versions matter. Even on supported laptops, outdated firmware may cause detection issues. Check ASUS's official support page for the latest compatibility list. The XG Mobile is NOT compatible with Thunderbolt or USB-C ports. ## Product Info The ASUS ROG XG Mobile GC31S-026 was released in early 2021. Warranty is 12 months from purchase for the unit and power cable, with ASUS Japan providing support via phone and online. Market positioning: high-end laptop graphics booster. The internal GeForce RTX 3080 is a custom chip (not the laptop RTX 3080) with 150W TGP. This provides roughly equivalent performance to a desktop RTX 3060 Ti to RTX 3070. The XG Connector's PCIe 3.0 x8 interface gives it a decisive bandwidth advantage over Thunderbolt 4 eGPUs, allowing the GPU to stretch its legs more effectively in GPU-intensive tasks. ## Best Use Cases * Creative professionals on the go: If you use a thin-and-light ROG Flow for travel but need heavy GPU power for video editing, 3D rendering, or AI work at your desk, the XG Mobile bridges that gap. Just plug in when you return home and get desktop-class performance. Not ideal if you don't already own a compatible ROG laptop. * High-end mobile gamers: Pair this with a ROG Flow Z13 or X13 for a lightweight gaming tablet that transforms into a 4K gaming rig. RTX 3080 can handle AAA titles at high settings on a 4K monitor. However, if your laptop already has an RTX 3070 or better, the upgrade may not justify the cost. * Space-constrained enthusiasts: Minimal desk setup? The XG Mobile takes up very little space and sits neatly beside your laptop. No need for a bulky desktop tower. But it adds a power brick and one thick cable to manage. ## Things to Consider The most significant limitation is compatibility: only a handful of ASUS ROG laptops work with the XG Connector. If you upgrade your laptop in the future, the new model must also have the same port, or the XG Mobile becomes useless. Performance wise, the 150W power envelope means this isn't a full-fat desktop RTX 3080. Expect around RTX 3060 Ti levels in practice. Also, for maximum performance, use an external monitor—rendering back to the laptop's internal display incurs a small overhead due to bandwidth inversion. If portability isn't a must, building a dedicated PC may offer better value and upgradeability. ## FAQ Q: How do I know if my ASUS laptop has the XG Connector port? A: Look for a rectangular port on the left or rear edge that's larger than USB-C. Check the product specs for "ROG XG Mobile compatible" or "XG Connector". Confirmed models include ROG Flow Z13 (all generations), ROG Flow X13, and certain ROG Zephyrus Duo models. The port is also labeled next to it on the chassis. Q: Can I use this eGPU with a non-ASUS laptop? A: No. The XG Connector is proprietary and electrically incompatible with Thunderbolt, USB-C, or any other standard interface. There is no adapter or hack available. This is strictly an ASUS ecosystem product. Q: How do I updat ### Product Disclosure (Amazon) - Manufacturer: ASUS - ASIN: B08XTGJK8L - Note: This article covers a manufacturer-made product based on Amazon listing details.