The original ROG Zephyrus Duo 15 (GX550) wowed us last year with its deftly executed dual-screen design, and now Asus has pumped up the performance. The 2021 GX551 model (starts at $2,199.99; $3,699.99 as tested) brings both AMD’s new Ryzen 5000 mobile processors and Nvidia’s GeForce RTX 30 series GPUs to bear, delivering improved gaming and media-editing performance. Despite the sky-high price of our test configuration (we’d recommend one of Asus’ lower-cost models, for several reasons), the base model of the GX551 actually costs less than its GX550 predecessor. A more-accessible entry point for this high-tech machine is a boon, and other tweaks and additions improve the build further. The Zephyrus Duo 15 is still a costly niche machine—a second screen remains a luxury rather than a necessity—but it’s a unique and appealing gaming laptop.
A Sleeker Look, the Same Streamlined Build
The design of the 2021 model is extremely similar to the original version, but its uniqueness warrants a rundown regardless. First, the obvious: the dual screens are the marquee feature, and are executed in very streamlined fashion. We’ll touch more on what they can do in a moment, but the concept is still impressive, as is the laptop’s staying slim and portable while housing the dual displays. The Duo measures 0.82 by 14.2 by 10.6 inches and weighs 5.3 pounds, identical to last year’s model and no bulkier than many conventional gaming rigs.
This year’s edition has some aesthetic changes: The lid looks different, with some new design flourishes, and Asus swapped the blue-gray color for an all-black look. (It looks a bit paler under our studio lights in the above photo, but rest assured, the paint job is very much a dark black.) The system looks stylish with the lid closed and sleek and high-tech when opened.
As with the original Zephyrus Duo, the second (“ScreenPad Plus”) display between the main screen and keyboard lifts on its hinges to angle itself toward you as you open the laptop lid. That makes it much more visible than a flat screen from a normal position, and it opens up ventilation beneath the display for improved system cooling. Asus has now utilized this layout both as a gaming solution and, with the ZenBook Duo 14, for general productivity, and it works well in both scenarios.
The ScreenPad Plus works as a fully usable second display, complete with touch capability. You can drag and drop any windows from the main display onto the second screen as you would with an external monitor (though doing so is slightly more difficult, as app windows and the cursor appear fairly small once you move them onto the ScreenPad Plus).
Fortunately, you get a pleasantly surprising variety of software customization options for the screen. For one, when you first grab a window, a tooltip-like bar pops up by your cursor and offers a couple of buttons to snap the window to the lower screen. This saves you the dragging, which can be awkward when done using the touchpad. You can also lock a persistent toolbar to the ScreenPad Plus, which offers a load of options such as a brightness control, an app navigator, a handwriting mode, shortcuts to Asus’ system software to control fans and lighting, and assorted sizing options.
I wouldn’t call the ScreenPad Plus essential—laptops have gotten by just fine all this time with one screen, after all—but it’s the type of luxury option you pay extra for, and unlike woodgrain trim in a sedan, a useful one at that. Since you can put virtually any window or application there, its usefulness really comes down to what you try to do with it.
Since this is a gaming laptop, a few usage scenarios stick out to me in particular. While I’m playing games, I’m usually also on Discord to voice-chat with friends. With a dual-monitor desktop setup, it’s easy enough to have the chat on another screen, but playing on a laptop requires you to minimize your game or attach a second screen. The ScreenPad Plus allows you to have Discord, or any other chat app, open at all times.
That’s not exactly a game-changer, but it’s the sort of convenience you enjoy when paying for a luxury feature like a second display. A software update that will greatly appeal to content creators, meanwhile, is integration with Adobe’s creative suite, in the form of a persistent control panel with customizable commands and shortcuts for Photoshop, Premiere Pro, After Effects, and Lightroom.
Two of the casualties of this unique screen setup are the keyboard and the touchpad. The keyboard is shifted to the front edge of the laptop to make room for the screen, and it’s mostly fine to use, but there’s really nowhere to rest your wrists. The keys themselves are individually backlit, which makes for fun customization options, and their travel distance and feedback make for a good enough typing experience.
It’s the touchpad that suffers more, compressed into a narrow right-hand layout that takes some getting used to. (Lefties may well loathe the location.) Gamers are famous for preferring external mice, but the pad is less than ideal for general browsing. It can, however, transform into an LED-lit numeric pad at the touch of a button in its top left corner.
Finally, we come to the ports. The left flank holds the power connector, a headphone jack, and a microSD card slot, while the right side is home to two USB 3.1 Type-A ports and one USB-C port.
The rest are located around back, likely because the rear half of both sides is devoted to cooling vents. Here you’ll find an Ethernet jack, an HDMI output, and another USB 3.1 Type-A port, completing an overall solid port selection.
There’s no webcam to be found, which is an unfortunate exclusion during this period of vastly increased remote work. Asus did upgrade the speakers, adding two forward-firing tweeters for richer sound.
Component Check: AMD and Nvidia Bring Their Latest
With the minor aesthetic and feature changes out of the way, we can get to the internals. This laptop’s core components are the stars of the show, upgraded on both the CPU and GPU side thanks to AMD and Nvidia respectively. We first tested a Ryzen 5000 series processor in the Asus ROG Flow X13 and it lived up to high expectations, so I was eager to see how one would perform in a larger 15.6-inch laptop. It’s also intriguing to get another look at Nvidia’s RTX 30 series laptop GPUs, which arrived to great anticipation after the success of their desktop counterparts but have proven something of a mixed bag in our tests so far.
The main display comes in two resolution and refresh-rate combinations: full HD (1080p) with a 300Hz refresh rate, and 4K UHD with a 120Hz refresh rate. The ScreenPad Plus is now available in full HD and UHD as well. Previously, the secondary display was only available in UHD (technically 3,840 by 1,100 pixels given its unusual dimensions), but the lower-res option effectively gives the system a lower starting price.
You can’t pick and choose screens in any combination—there are three models of the Zephyrus Duo, and the screens are tied to other components. The $2,199.99 base model combines a Ryzen 7 5800H processor, 16GB of memory, a 1TB solid-state drive, a GeForce RTX 3060 GPU, and the full HD versions of both the main display and ScreenPad Plus. This is a significant savings over the original GX550, which started at $2,999.99. The middle model comes in at $2,899.99, pairing the same displays with a Ryzen 9 5900HX chip, 32GB of RAM, and RTX 3070 graphics.
Our review unit is the top-of-the-line version, an eye-watering $3,699.99 with the UHD 120Hz display, UHD ScreenPad Plus, Ryzen 9 5900HX processor, 32GB of memory, 2TB of SSD storage, and GeForce RTX 3080 GPU. Personally, I don’t think the huge price jump for the dual 4K screens and RTX 3080 are worth it (more on that in the performance section), but if your budget knows no bounds, this may be the all-out config for you. At least with this screen, you aren’t giving up a high refresh rate for higher resolution as with many 4K displays of the past, even if gaming at 4K is still challenging even for top-end components.
Performance Testing: Blistering Ryzen 9 Speed, RTX 30 Series Boost
To get a sense of how the new components perform, I’ve put the Zephyrus Duo GX551 up against not only its predecessor but competing high-end gaming laptops. The table below shows their names and specs. (See more about how we test laptops.)
The Alienware m15 R4 is our reigning Editors’ Choice award holder for 15-inch gaming laptops and to date the best RTX 30 series performer we’ve seen, making its inclusion here essential. The MSI GS66 Stealth provides another look at an RTX 3080 as a direct competitor, while the Asus TUF Dash F15 brings Intel’s “Tiger Lake-H” processors into the mix. Finally, the previous Zephyrus Duo shows us how Nvidia’s RTX 2080 Super (Max-Q) stacks up against its successor.
Productivity, Storage, and Media Tests
PCMark 10 and 8 are holistic performance suites developed by the PC benchmark specialists at UL (formerly Futuremark). The PCMark 10 test we run simulates different real-world productivity and content creation workflows. We use it to assess overall system performance for office-centric tasks such as word processing, spreadsheet jockeying, web browsing, and videoconferencing. PCMark 8, meanwhile, has a storage subtest that we use to assess the speed of the system’s boot drive. Both tests yield a proprietary numeric score; higher numbers are better.
This Ryzen 9 chip is blisteringly fast, opening a gap in PCMark 10 that we rarely see in equivalent machines—in fact, the highest PCMark 10 score we’ve recorded from a laptop to date. To some extent, a higher score on this test doesn’t matter too much for daily use: past a certain threshold, all of these laptops are more than fast enough for everyday jobs and multitasking. But it does hint at the potential for more strenuous uses, which leads us to our next tests.
Next is Maxon’s CPU-crunching Cinebench R15 test, which is fully threaded to make use of all available processor cores and threads. Cinebench stresses the CPU rather than the GPU to render a complex image. The result is a proprietary score indicating a PC’s suitability for processor-intensive workloads.
Cinebench is often a good predictor of our Handbrake video editing trial, another tough, threaded workout that’s highly CPU-dependent and scales well with cores and threads. In it, we put a stopwatch on test systems as they transcode a standard 12-minute clip of 4K video (the open-source Blender demo movie Tears of Steel) to a 1080p MP4 file. It’s a timed test, and lower results are better.
We also run a custom Adobe Photoshop image editing benchmark. Using an early 2018 release of the Creative Cloud version of Photoshop, we apply a series of 10 complex filters and effects to a standard JPEG test image. We time each operation and add up the total. As with Handbrake, lower times are better here.
As you can see, the Ryzen 9 5900HX’s dominance continued in all three of these tests. The Cinebench and Handbrake results demonstrate the chip’s superiority in longer multithreaded workloads, while it’s not as dominant (but still highly efficient) with the shorter burst tasks of Photoshop. Intel’s 10th Generation Core i9 trailed significantly in Cinebench but less so in the rest, while anything below that was mostly left in the dust (including the “Tiger Lake-H”).
This means the Zephyrus Duo genuinely doubles as a media editing and content creation laptop. Some gaming laptops toe that line, and Core i9 machines usually qualify, but the GX551 legitimately delivers workstation-class performance for these types of jobs. The dual 4K displays are useful for productivity and media editing, too, so the whole concept comes together for work as well as gaming.
So now we know that the processor sings, and AMD has another multi-threaded muscle chip on its hands. Will the GPU results be as strong? On to the next tests…
Graphics and Real-World Gaming Tests
3DMark measures relative graphics muscle by rendering sequences of highly detailed, gaming-style 3D graphics that emphasize particles and lighting. We run two 3DMark subtests, Sky Diver and Fire Strike, which are suited to different types of systems. Both are DirectX 11 benchmarks, but Sky Diver is more suited to midrange PCs, while Fire Strike is more demanding and made for high-end and gaming PCs to strut their stuff. The results are proprietary scores.
Next up is another synthetic graphics test or gaming simulation, this time from Unigine Corp. Like 3DMark, the Superposition test renders and pans through a detailed 3D scene and measures how the system copes. In this case, it’s rendered in the eponymous Unigine engine, offering a different 3D workload for a second opinion on each laptop’s graphical prowess.
These synthetic tests are helpful for measuring general 3D aptitude, but it’s hard to beat full retail video games for judging gaming performance. Far Cry 5 and Rise of the Tomb Raider are both modern, high-fidelity titles with built-in benchmarks that illustrate how a system handles real-world gameplay at various settings. We run them at 1080p resolution at the games’ medium and best image-quality presets (Normal and Ultra for Far Cry 5 under DirectX 11, Medium and Very High for Rise of the Tomb Raider under DirectX 12).
Clearly, there’s no doubt the Duo’s RTX 3080 is objectively as potent as you’d hope for such a top-ranked GPU in such a top-priced laptop. The synthetic scores show raw power, while the game frame rates are far enough above 60fps to make use of the 120Hz screen. That’s why you buy a flagship gaming rig if you’re an enthusiast.
That said, things get less rosy when you bring the competition into the mix. Not only did the MSI’s GeForce RTX 3080 outrun its counterpart in the new Zephyrus, the latter failed to surpass the Alienware’s RTX 3070. I also ran Metro Exodus as a ray-tracing test, since the 30 series GPUs should show particular improvement there with the RTX 3080 the most capable of the batch. Using the RTX settings preset, the GX551 averaged 66fps at 1080p and 40fps at 4K, while the Alienware was only barely slower, at 61fps and 36fps respectively.
As discussed in our initial testing deep-dive article, GeForce RTX 30 series GPUs are configured at a wide range of wattages, which can cause performance to vary from one machine to the next. That’s also true for RTX 30 series GPUs with the same ostensible name (say, one RTX 3070 versus another, as you can see by the results from Alienware and the Asus TUF Dash F15). On top of that, Nvidia’s Max-Q nomenclature has become more muddied and general if not outright vague, so it’s difficult to know what you’re getting just from the name.
Frankly, it’s hard to see why you’d pay a lot more for a GeForce RTX 3080 laptop over an RTX 3070 model based on the testing data we’ve collected so far. If one manufacturer happens to offer an RTX 3080 config that competes with or even undercuts the price of another’s RTX 3070, go for it, but otherwise there are clear diminishing returns as you go up the GeForce RTX 30 series stack. Part numbers may tell you one thing on paper, but between varying implementations and unpredictable price tags, it’s more important than ever to look at independent testing. The Zephyrus Duo GX551’s performance is undeniably high, but not quite commensurate with its stratospheric price. Again, the saner-priced configs seem much more worthwhile.
Battery Rundown Test
After fully recharging the laptop, we set up the machine in power-save mode (as opposed to balanced or high-performance mode) where available and make a few other battery-conserving tweaks in preparation for our unplugged video rundown test. (We also turn Wi-Fi off, putting the laptop in airplane mode.) In this test, we loop a video—a locally stored 720p file of the same Tears of Steel short we use in our Handbrake test—with screen brightness set at 50 percent and volume at 100 percent until the system quits.
This battery life is reasonable enough, especially when you consider the power-sapping components and dual UHD screens. The Duo won’t last you all day, but it won’t die after a measly two hours like some gaming laptops. You’ll be able to take a quick trip off the charger, or not have to plug in as soon as you plop down on the couch.
Building a Better Two-Screen Machine
This ROG Zephyrus Duo 15 is a complex machine, and it’s hard to give a definitive answer as to whether it’s worth your hard-earned money. The clearest takeaway is this: The GX551 is generally a luxury buy given its price and non-essential dual-screen design, but it’s very well executed, and the base price is actually quite reasonable for what it is.
The flagship configuration we reviewed, on the other hand, is harder to recommend unless money is no object. The UHD screens and 2TB SSD bring a significant price hike, as does the RTX 3080 GPU, but you’re not getting much more performance than you could squeeze from a less expensive (but still quite premium) laptop. The Alienware m15 R4 retains our Editors’ Choice among premium gaming notebooks for its balance of price and power, but the Zephyrus Duo remains an impressive and appealing machine.
