The $499.99 Razer Core (pictured) is a Thunderbolt 3 (USB-C) external graphics enclosure. It designed to allow users to transform a notebook (PC, not Mac) into a desktop gaming experience. It offers plug and play support with compatible graphics cards. With the Razer Core, you can upgrade or customize your preferred level of performance with support for full-length, double-wide PCIe desktop graphics cards (sold separately, of course).
The Razer Core is targeted to gamers, but it offers appeal to just about any sort of “power user.” Intel has also introduced two external graphics enclosures that let compatible notebooks connect a desktop graphics cards and utilize their increased graphical horsepower. This means laptop users can experience graphics far superior to what a notebook can do since even the best notebook graphics card can't compete with top-of-the-line desktop cards.
What’s more, Mac laptops can't be upgraded with better graphics cards. Even if you could, mobile graphics cards are more expensive than the equivalent desktop cards. An Apple version of the Razer Core could be a hot seller for owners of MacBooks, MacBook Airs, and even MacBook Pros.
Come to think of it, even if Apple does launch the “5K Thunderbolt Display With GPU” (my moniker, not an official one), there’s no reason an Apple GPU box couldn’t be sold in addition to the monitor.