Asus ROG Zephyrus S GX531GS (i7-8750H, GTX 1070 Max-Q, FHD) Laptop Review

In line with the current trend, Asus uses a slim-bezel design in the ROG Zephyrus S GX531. Due to the slim display frame, the width of the notebook has dropped from 37.9 cm (~14.9 in) in the predecessor to 36 cm (~14.2 in), leading to a more compact presentation. However, this goes only for the width, since the depth has even increased slightly compared to the GX501 (26.8 vs. 26.2 cm, ~10.6 vs. 10.3 in). At first glance, it might look great that Asus has decreased the thickness from 17.9 to 15.8 mm (~0.7 to 0.62 in, keywords: design and mobility). However, the obsession with slimness also has some negative aspects, as we will point out in the course of this review. The slim-bezel devices from MSI, Gigabyte, and Razer range between 17.3 and 18 mm (~0.68 - 0.7 in), which is also very slim. 

In terms of the weight, there are no surprises. With the exception of the particularly light (but also less sturdy) GS65 Stealth, all the competitors weigh around 2.1 kg (~4.6 lb). Thanks to the low weight and compact measurements, the GX531 can be carried around comfortably, which should please those gamers who are on the road a lot.

There are also no complaints about the quality of the case. Similar to the predecessor, Asus has predominantly used metal here as well, which ensures an elegant look and feel. However, the dark surfaces attract fingerprints. Whether you like the two-part design of the lid or not is a matter of taste. The manufacturer has combined a sand-blasted finish with a brushed finish here. We would consider the workmanship of our test unit good, and all the elements transition cleanly into one another. 

However, Asus could improve a bit on the hinges. Even though the lid can be opened with one hand and also remains fairly stable during tremors of the surface, the maximum opening angle is extremely small. One of the characteristics of the 15-incher that stands out is the very unusual construction of the bottom that we already know from the GX501. When opening the hinge, part of the case bottom also swings open, creating a gap of several millimeters (1 mm = 0.04 in) that is supposed to improve the air circulation and provide some cooling.

Connectivity

Basically, we were disappointed by the connection equipment. In contrast to its predecessor, the GX531 does not have a Thunderbolt-3 port anymore, although in 2018 it is the standard of notebooks in this price range. After all, the Gigabyte Aero 15X v8, the Razer Blade 15, and the MSI GS65 also offer the corresponding connections. A combined audio port for headphones and microphone is also meager. 

The choice of USB ports may also lead to some users shaking their heads. While two 3.1-Gen2 ports (1x Type-A, 1x Type-C) on the right side are nice, the left side has to be content with two ancient 2.0 ports (Type A) in addition to the single 3.0 port (Type-C). Anyone who wants to connect a monitor via DisplayPort instead of HDMI also needs a Type-C adapter, since Asus has not built in a dedicated DisplayPort connection – annoying! Buyers will have to make do without a card reader or an RJ45 port as well.

We can offer praise for the high Wi-Fi speed. Intel's brand-new Wireless AC-9560 chip is used as the communication module. At around 700 Mb/s in sending and receiving, the GX531 takes the first place among the competitors in our WLAN test (1 m distance to our Linksys EA8500 reference router), even if the differences often remain marginal.

Unfortunately, the GX531 has inherited the lack of maintainability from the GX501. While in other gaming notebooks you can quickly and fairly easily access the insides by taking off the case bottom, the process is much more complicated and less user-friendly in the ROG Zephyrus S. If you take off the fold-out bottom construction via Philips screwdriver, you only get access to the two case fans and nothing else (see image above).

Only a key-ring and several stickers were included with our test sample. The power is provided by a 230-watt power supply that measures about 16.5 x 7.5 x 3 cm (~6.5 x 3 x 1.2 in) and weighs almost 0.6 kg (~1.3 lb).

In Germany, Asus offers a two-year warranty for the notebook. Please see our Guarantees, Return policies and Warranties FAQ for country-specific information.

For cooling and space reasons, it's not only the keyboard that is positioned in an unusual place, the touchpad is as well. With a width of only 6 cm (~2.4 in), the surface turns out to be very small, which makes controlling horizontal moves on the 16:9 screen rather awkward. The depth of 8 cm (~3.1 in) does not offer much help there either.  

At least it is easy to slide your fingers on it, thanks to the smooth finish. On the other hand, the precision could have been better. We find nothing unusual in the multi-touch support. You can zoom and scroll through documents and websites comfortably. Good: In order to make up for the lack of a number pad, Asus builds-in a number-pad mode, which is toggled with a special key.

While the GX501 was equipped with a G-Sync-capable 120-Hz display, you get a 144-Hz panel without G-Sync in the GX531, which delights with a very short response time. Instead of 28-33 ms it is now only 7-10 ms. This is a clear improvement that also prevents smudging even in fast games such as ego-shooters.

Despite the slim case, Asus has equipped the ROG Zephyrus S with high-end components that are otherwise found in significantly thicker laptops. At this point we should mainly mention the hexa-core CPU, which offers a lot of power reserves and brings sufficient future-proofing for the coming years. For the GPU, the manufacturer uses Nvidia's power-saving Max-Q design, which was developed for extremely slim laptops. 16 GB of DDR4-RAM and a PCIe-SSD are also in sync with the times.

In the benchmarks, the GX531 delivers an exceedingly good performance. In the multi-core tests of Cinebench R15 and R11.5, the 15-incher places second, and only the Gigabyte Aero 15X v8 is able to move slightly ahead. The advantage to the old Kaby-Lake generation is particularly impressive, and the Core i7-7700H quad-core of the GX501 is beaten by more than 50%.

However, this huge performance advantage only lasts for a short time, since like many other Coffee-Lake notebooks the GX531 is unable to maintain its full CPU Turbo for very long. In our Cinebench loop, you can see that the performance drops by about 10% starting from the second run. Instead of 3.9 GHz (corresponding to the maximum Turbo boost during load of all cores), the Core i7-8750H then "only" achieves 3.0-3.2 GHz. Thus the Cinebench score settles down at the same level as the MSI GS65 Stealth, placing in the middle between the Gigabyte Aero 15X and the Razer Blade 15.

The system performance benefits primarily from the PCIe-SSD. Thanks to this modern technology, Windows is able to boot up exceptionally fast and also responds comfortably fast otherwise. Installations, program starts, and data transfers do not turn into an ordeal either. The synthetic benchmarks such as PCMark 10 confirm this subjective impression. With an overall score of 5170 points, the GX531 places at the top of the test field.

The gold medal in PCMark 10 is slightly surprising, since the pure SSD performance does not quite reach the level of the competitors. In CrystalDiskMark 5.2, the Razer Blade 15 (Samsung PM961) and the MSI GS65 (Samsung PM981) achieve 17% and 19% better results, respectively. For the old GX501 (Samsung SM961), it is even an advantage of +39%. In terms of its performance, the 512-GB drive by Western Digital (SN520) is more at the level of the Toshiba SSD in the Gigabyte Aero 15x.

Unfortunate: According to our information, the GX531 offers only a single M.2 slot. In order to expand the storage, you would need to remove the current SSD and replace it. Usually gaming notebooks offer at least two M.2 slots or a combination of an M.2 SSD and a 2.5-inch HDD.

Nvidia's GeForce GTX 1070 Max-Q is the perfect choice for demanding gamers who prefer a compact case suitable for travel. The DirectX-12 model is based on the Pascal architecture, and similar to its standard version, it brings 2048 shaders as well as 8 GB of GDDR5 video storage, which is connected via the 256-bit connection.

There are larger differences in the clock speed. While the GTX 1070 achieves a base value of 1443 MHz, the Max-Q-Edition only runs at 1101 MHz. Thanks to the automatic GPU Turbo, much higher values are possible during 3D applications. The render test of the GPU-Z tool attests the GX531 with up to 1544 MHz. During everyday gaming, you can expect around 1350 MHz, which is confirmed by our tests with the Unigine Heaven 4.0 benchmark and The Witcher 3.

On the other hand, the other manufacturers did not fall asleep either, as you can see in the comparison chart. In 3DMark 11, the competitors move ahead by 2-11%. However, this is not necessarily the result of the GPU clock speed but can also be connected to the driver version.

The endurance test (60 minutes of The Witcher 3 @ FHD/Ultra) did not bring anything unusual to light, neither in terms of the CPU nor the GPU (temperatures, clock speed, etc.).

Update 11/09/18: Upon request by Asus, we also briefly tested the performance in Turbo mode. Due to the higher clock speeds, the benchmark results improve by 10% or more. However, this goes at the expense of an increased noise development, which is hefty anyways. For example, the Turbo mode produces 55 dB instead of 51 dB, which is an annoyingly loud noise level.

The GeForce GTX 1070 Max-Q has no problems at all in the native Full HD resolution. 1920x1080 pixels and (very) high details can be delivered smoothly even in current AAA games such as Black Ops 4, Shadow of the Tomb Raider, and Forza Horizon 4.

The frame rate hardly ever drops below 60 FPS, showing the 144-Hz screen to its best advantage. The significantly more expensive GeForce GTX 1080 (Max-Q) would only be worthwhile for higher resolutions in the QHD and UHD ranges.

During idle, the 15-incher does not present its best side either. Although the fans ideally are quiet or run at a low speed (32-33 dB), from time to time the cooling revs up to more than 40 dB. This happens sometimes without any discernible reason. However, the same behavior can be seen in many other laptops as well.

Under the hood, there is no reason for concern. Even in the stress test with the FurMark and Prime95 tools, the CPU and GPU never reach the critical 90-°C mark (194 °F). However, the average temperatures in the 70-80-°C range (158-176 °F) are maintained with throttling. While the Core i7-8750H only throttles minimally to 2100 MHz (base clock speed: 2200 MHz), the GeForce GTX 1070 can drop to 700 or 800 MHz at times. But this behavior is limited to extreme scenarios that hardly ever happen in practice.

Considering the form factor and the slim thickness, the sound quality is more than acceptable, although you should not expect wonders with the GX531. According to our audio analysis, the only area lacking is the bass. While due to the lack of a subwoofer, the bass is neglected, the 2.0 system (with the speakers sitting behind the hinge) reproduces the mids and highs fairly cleanly and accurately. Furthermore, the maximum volume of 81 dB is sufficient for small to mid-size rooms.

Those who want to adjust the sound individually can have some fun with the two preinstalled audio tools, Sonic Rader and Sonic Studio.

The power hunger of our test unit is strange in our opinion. Due to the graphics switching, the power consumption during idle should theoretically be lower than that of the GX501 with G-Sync. However, this is hardly the case, and the GX531 has to struggle with some strange consumption peaks (the CPU clock speed regularly jumps higher). Despite having a similar CPU and GPU, the competitors consume less power, which also has a strong effect on the battery life.

Not only does the GX531 blunder in terms of the power consumption, but unfortunately it also fails with the battery capacity. Compared to the competitors, 50 Wh is very meager and unworthy of a notebook targeted for mobility. The laptops from Razer (80 Wh), MSI (82 Wh), and Gigabyte (94 Wh) that last significantly longer than the GX531 in all scenarios are proof that slim-bezel gaming notebooks can contain batteries with twice the power. In ideal conditions, the Aero 15X can last more than 12 hours without a recharge, and a maximum of 8.5 hours for the GS65 and up to 6.5 hours for the Blade 15 are also respectable. In contrast, the ROG Zephyrus S can only manage up to 3.5 hours, which does not surpass the result of the predecessor and causes the overall evaluation to drop behind that of the competitors.