Razer Core X
Can it really transform your laptop into a desktop-stomping gaming rig?
With the latestgen mobile CPUs from Intel now offering six-core CPUs that can fit into super slim ultrabooks, an external GPU (eGPU) accelerator that bolts onto your ultrabook has perhaps never made more sense. Working over Thunderbolt 3 or USB 3.1, Razer’s Core X is the company’s third eGPU enclosure, and it lets you outsource graphicsheavy tasks from your laptop to a desktop PCIe graphics card — in theory giving even an ultrabook a serious kick in the graphics department. Compared to its forebear, the Core V2, the Core X offers a bigger power allocation, uses the newer Thunderbolt spec and comes at a significantly cheaper price.
The release of the Core X also neatly lines up with a new macOS feature that arrived in March 2018, which provides official support for a number of AMD desktop GPUs using an Apple-approved eGPU enclosure, including the Core X. This means existing MacBook Pros can be boosted by combining an AMD Radeon (or Radeon Pro) GPU with the Core X for a serious GPU bump.
The 6.4kg Core X is roughly the size of a miniITX PC tower and comes wrapped in a thick piece of curved aluminium which, while it looks impressive, also makes up at least half of the unit’s weight. Folded inside this premium frame is a 650W power supply that can run GPUs up to 500W, a PCIe-equipped daughter board with a Thunderbolt connection, and a large 120mm cooling fan. That’s basically all the parts you need to turn your daytime ultrabook into a nighttime gaming godfather. You’ll have to BYO desktop GPU and slot it inside the cooling frame, but the Core X is compatible with the last three generations of Nvidia GTX GPUs, Nvidia’s Quadro workstation range and AMD’s Radeon R9, RX and WX graphics cards, so you shouldn’t have any trouble finding something.
For testing, we installed a GeForce GTX 1080 in the Core X and paired it with a 13-inch, 2018-model Razer Blade Stealth ultrabook equipped with a Core i7-8550U CPU and 16GB of RAM. On 3DMark’s toughest graphical benchmark, that combination pushed out a solid score of 4,306, around 15% less than what you’d expect from a similarly-equipped desktop PC using a GeForce GTX 1080. However, those synthetic benchmark numbers didn’t quite hold up in real-world testing. At 1080p resolution with Ultra graphics settings, frame rate averages were of just 33.63fps on modern titles like Ghost Recon Wildlands — around half the 59fps what we saw with our GTX 1080-equipped desktop. While not everything dropped that far, we did note GPU performance sacrifices 40–50% in many games — a tough pill to swallow if you’ve forked out for a top-shelf GTX 1080.
The Thunderbolt 3 connection is the main bottleneck. Other tests show the performance loss is much lower with entry-level or midrange GPUs. While you can boost performance on faster cards by about 10% if you connect an external monitor directly to the GPU output, even that’s not quite enough to make this a universally appealing solution to the conundrum of gaming on an ultrabook. We await the release of Thunderbolt 4 with bated breath.