Many people like their work laptops tiny and light and their gaming laptops screamingly fast and crammed with the latest technology. Sadly, the laws of physics conspire to keep us from getting both in a single device, but Asus gives it a shot with the combination of its ROG Flow X13, a 13-inch, 2.9-pound two-in-one laptop, and the XG Mobile, a compact external-GPU-plus-dock combo device. The power pairing of the new eight-core AMD Ryzen 9 5900HS processor in the laptop and Nvidia GeForce RTX 3080 mobile GPU in the external module combine to deliver a multifaceted, fast system that's imperfect, but still much more than the sum of its parts.

It's not the first time we've seen a laptop-plus-eGPU combo as a workaround to the tradeoff between power and size, but unlike Lenovo's thin-and-light lightweight gaming laptop with an external graphics processor, you can still get in some decent gameplay without the eGPU, because the X13 doesn't ditch the discrete graphics. Its GeForce GTX 1650 isn't a very powerful GPU, but it's enough to handle basic gaming and modest photo editing.

In addition to the RTX 3080 in the XG Mobile, the unit has its own 280-watt power supply that can drive the laptop, four USB-A ports, DisplayPort and HDMI connections, an Ethernet jack and an SD card slot. Because it uses the mobile Nvidia part, the XG Mobile is relatively small: 55 by 208 by 29 millimeters, and 2.2 pounds (1 kg).

It has a proprietary architecture for connecting the laptop and XG Mobile, with a single cable that combines USB-C for the hub and power delivery and an eight-lane dedicated connection to the PCI bus. Alienware's Graphics Amplifier also uses a proprietary connector, but it only has a four-lane bus. When not attached to the XG, the USB-C half of the connector works as... a USB-C port. 

Asus offers two configurations of the X13: one equipped with the 5900HS and a 120Hz, 1,920x1,200-pixel display, or a 5980HS-based "Supernova" edition with a 3,840x2,400, 60Hz screen. The Supernova only comes in a bundle with the XG Mobile for $3,300, while you can buy the standard-version bundle for $2,800 or the X13 and XG separately for $1,500 each. I tested the standard pairing. (The two products are not widely available outside the US, though we've seen UK resellers sell the Flow X13 for £1,500 alone or in a bundle with the XG Mobile for £2,900. That converts to about AU$2,700 and AU$5,200.)

Asus ROG Flow X13 with XG Mobile

Price as reviewed	$2,800
Display	13.4-inch 1,920x1,200-pixel IPS touchscreen display 120Hz
PC CPU	3.3GHz AMD Ryzen 9 5900HS
PC Memory	16GB LPDDR4x SDRAM 4,266MHz
Graphics	4GB Nvidia GeForce GTX 1650 Max-Q; 16GB GeForce RTX 3080 mobile in XG Mobile
Storage	1TB SSD; SD card slot in XG Mobile
Ports	2x USB-C, 1x USB-A 3.2, 1x HDMI 2.0b; 1x HDMI 2.0, 1x DisplayPort 1.4, 4x USB-A 3.2 in XG Mobile
Networking	Intel Wi-Fi 6 AX200 (802.11ax), Bluetooth 5.2; RJ45 Gigabit Ethernet jack on XG Mobile
Operating system	Microsoft Windows 10 Home (2004)
Weight	2.2 pounds (998 grams)

The Ryzen 9 5900HS processor turned in AMD's usual stellar multicore performance, as well as excellent single-core performance, narrowing the gap significantly with Intel. (The Ryzen 9 5980HS model should blow past it entirely.) I tested in Performance mode, which balances all the relevant variables -- noise, heat and so on -- but beyond that there's a noisy Turbo mode and you can overclock the chip as well. 

So if you're willing to play with the settings a bit, you can eke even more speed out of the processor. With the XG Mobile connected it performs slightly better, and the RTX 3080 mobile GPU is fast enough for you to get your 1440p gaming jollies without breaking a sweat, and it can hit 4K with some compromises. The combination of the CPU and GPU also turns the X13 into an eminently portable creative powerhouse. Because the GPU doesn't compete with the rest of the heat-generating components in the laptop, I expect it will continue to perform at the top of the mobile class, even compared with bigger 17-inch laptops.

Before you plonk down your hard-earned bucks, however, note that Asus will be refreshing the X13 with new Nvidia discrete graphics that will likely deliver even better performance. And the downside of Asus' trade paperback-sized XG is the inability to upgrade the GPU as you can with a typical eGPU.

By design

I have no problem with the proprietary connection for the XG Mobile. Thunderbolt wouldn't have worked for an eGPU for a variety of reasons. For one, it throttles the connection between the GPU and the main system, and splits the bandwidth among the other connections. That means it couldn't power the hub without taking a hit. Plus, when the eGPU is connected, the system disables the integrated GPU so it can allocate the power savings to the eGPU. But there's an even more notable reason: AMD doesn't support Thunderbolt.

While the USB-C ports support external displays, there just aren't enough of them, which Thunderbolt would have the bandwidth for. There isn't even a passthrough USB-C on the XG Mobile. 

Both the X13 and XG have pleasant physical designs, textured to let you have a firmer grip on them when carried. In fact, I only have one complaint about them: The nonremovable cable on the XG is a bad combination of very stiff and very short, which seriously limits your flexibility for placing them relative to each other. If you're using the kickstand to sit the XG upright, jostling the laptop knocks it over, and flipping the laptop into any of the tablet modes without detaching it is awkward.

Detaching and connecting the XG to the X13 is also a little more annoying than I'd like, which might escalate to frustrating if you want to frequently connect and disconnect. To connect it, you plug it in and slide a lock button, but you have to wait for the system to pop up a dialog for you to enable it, then wait some more while it thinks. Occasionally the dialog doesn't pop up, so you have to go searching to find and run the utility manually. If you detach it without going through the utility, the next time you boot without the XG connected the laptop throws up dire warnings about potential instability (which admittedly didn't seem to pose any problems).

In other ways, the X13 is a run-of-the-mill small two-in-one. The keyboard is far more oriented to work than play -- it has good travel and a bouncy feel that makes it comfortable to type on -- but the ability to rotate the display around with the keyboard in back makes it better suited to use with an external gaming keyboard than a clamshell. 

The display is... fine. A 120Hz refresh rate is a perk when you don't plan to connect to an external gaming monitor, but the screen is dimmer than you see these days on premium laptops, making it a meh choice if you work outdoors at a cafe or park. Battery life ran almost seven hours on our tests, which is good but not outstanding. You can extend that if you dial back the settings, but you really shouldn't have to. And if you do, you may take a noticeable performance hit, depending upon what you're doing.

I love the idea of the ROG Flow X13 and XG Mobile, but the execution could use a little refinement given the price. It's not overly expensive for what you're getting, but I'd rather not have to futz around as much to make it work optimally. If you're willing to put in the effort, though, it's a welcome way to balance a travel-friendly work laptop with one that can tackle your heavyweight gaming.

Geekbench 5 (multicore)

Razer Book 13 (late 2020)

Razer Blade Pro 17 (early 2020)

Asus ProArt StudioBook One

Asus ROG Flow X13 with XG Mobile

Asus ROG Zephyrus G14

Cinebench R20 CPU (multicore)

Razer Book 13 (late 2020)

Razer Blade Pro 17 (early 2020)

Asus ProArt StudioBook One

Asus ROG Zephyrus G14

Asus ROG Flow X13 with XG Mobile

Cinebench R20 CPU (single core)

Razer Blade Pro 17 (early 2020)

Asus ProArt StudioBook One

Asus ROG Flow X13 with XG Mobile

Razer Book 13 (late 2020)

Shadow of the Tomb Raider gaming test

Asus ProArt StudioBook One

Razer Blade Pro 17 (early 2020)

Asus ROG Flow X13 with XG Mobile

3DMark Fire Strike Ultra

Asus ROG Zephyrus G14

Razer Blade Pro 17 (early 2020)

Asus ProArt StudioBook One

Asus ROG Flow X13 with XG Mobile

3DMark Port Royal (RTX)

Razer Blade Pro 17 (early 2020)

Asus ROG Flow X13 with XG Mobile

Asus ProArt StudioBook One

SpecViewPerf 13 SolidWorks (4K)

Razer Blade Pro 17 (early 2020)

Asus ROG Flow X13 with XG Mobile

Asus ProArt StudioBook One

System configurations

Asus ProArt StudioBook One	Microsoft Windows 10 Pro (1909); 2.6GHz Intel Core i9-9980HK; 64GB DDR4 SDRAM 2,666MHz; 24GB Nvidia Quadro RTX 6000 with Max-Q Design; 1TB SSD
Asus ROG Flow X13 with XG Mobile	Microsoft Windows 10 Home (2004); 3.3GHz AMD Ryzen 9 5900HS; 6GB DDR4 SDRAM 4,266MHz; 4GB Nvidia GeForce GTX 1650 (16GB GeForce RTX 3080 mobile in XG Mobile)
Asus ROG Zephyrus G14 (GA401IV)	Microsoft WIndows 10 Home (1909); 3.0GHz AMD Ryzen 9 4900HS; 16GB DDR4 SDRAM 3,200MHz, 6GB Nvidia GeForce RTX 2060 with Max-Q Design, 1TB SSD
Razer Blade Pro 17 (early 2020)	Microsoft Windows 10 Home (1909); 2.3GHz Intel Core i7-10875H; 16GB DDR4 SDRAM 3,233MHz; 8GB Nvidia GeForce RTX 2080 Super Max-Q; 1TB SSD
Razer Book 13 (late 2020)	Microsoft Windows 10 Home (64-bit); 2.8GHz Intel Core i7-1165G7; 16GB DDR4 SDRAM 4,267MHz; 128MB Intel Iris Xe graphics; 256GB SSD