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Asus RoG G20CB review – hot and bothered

Our Rating :
Price when reviewed : £1500
inc VAT

Fantastic chassis design, but this compact gaming PC simply isn't good value


Processor: Quad-core 3.4Ghz Intel Core i7-6700, RAM: 16GB, Front USB ports : 2x USB3, Rear USB ports: 4x USB3, 2x USB2, Total storage: 128GB SSD, 2TB hard disk, Graphics card: 4GB Nvidia GeForce GTX 970, Display: None, Operating system: Windows 10 64-bit Home


Compact PCs are among the most impressively-engineered devices we test. From the likes of the Alienware Alpha and even the bargain Dell Inspiron Micro, we’re often amazed by simply how much processing power can be packed into such a tiny space. As such, we had high hopes for the Asus RoG G20CB. In terms of performance per cubic inch, it must be the most powerful PC we’ve ever tested, and its slate-like design certainly catches the eye when you walk into a room. However, it also comes with an equally eye-watering price.

Design and build

We’ll get onto the flaws in a bit though, for starters let’s enjoy the good stuff. First, simply nothing matches the G20CB for looks. The angled styling of the matt black chassis and the science-fiction, backlit labyrinth touches around the edges looks superb. The red core that runs through the the middle of the whole machine is a notable highlight, although the strong colour does limit the potential of the pre-installed Asus Aegis software which, among other things, lets you customise the backlit LEDs to glow in different colours. Not a lot goes with metallic red, so I found myself sticking to the preset red LEDs.

With a horizontal footprint of just 358x340mm or a 108×340 footprint when placed on its side, the G20CB will fit just about anywhere, be it on your desk or under your TV. It’s immensely practical, which is something worth paying for if space-saving is your prime motivator. There is one caveat to this: the external power supply is, in fact, two large power bricks housed inside a plastic frame, making them much bulkier than a traditional PSU.

On the front of the chassis you’re afforded two red-accented USB3 ports and two 3.5mm audio jacks. There’s also a pop-out DVD drive here, although considering how much the G20GB costs this is a bit disappointing, as it would have been nice to get a Blu-ray drive for Full HD playback.

At the rear there are six USB ports, which are made up of two USB3.1, two USB3, and two USB2 ports denoted by light blue, dark blue and black connectors respectively. There’s also a Gigabit Ethernet port and six 3.5mm audio jacks. There’s no optical S/PDIF for use with some soundbars and older AV receivers, but the graphics card (more on this later) has three DisplayPort connectors, an HDMI port (through which you can output audio of course) and a DVI port. In short, the physical design of the Asus RoG G20CB isn’t just a resounding success, it’s the best part of this PC.

Keyboard and mouse

Asus’ choice of keyboard is less impressive. The wireless keyboard and mouse combo supplied with our review unit is about as basic as they come and really don’t match the G20CB’s premium ambitions. The keyboard is soft and frustrating to type on while the mouse lacks any extra inputs beyond its left, right and scroll wheel buttons. If you’re seriously considering making a purchase, budget in a better keyboard and mouse, plus you’ll probably want a games controller, too, if you’re going to be using it as a living room PC.


For such a small PC, the specification is potent – at least on paper. There are several models available, but the model on test here is the most expensive you can buy in the UK today. You’re supplied with an Intel Core i7-6700 processor that runs at a base clock speed of 3.4GHz, boosting to 4GHz when thermal conditions allow for it. It’s also paired with 16GB of DDR4 RAM.

For a gaming PC, a Core i7 processor is nothing more than showing off for most people; you’ll only take advantage of its high Turbo Boost speed and multi-tasking-friendly Hyper-Threading technology if you’re a video editor or avid game streamer. For everyone else, a mid-range Intel Core i5 would have done just fine. Then again, maybe this isn’t a PC for those who settle for mid-range.

The Expert Reviews benchmarks, which challenges PCs to photo rendering, video conversion and multitasking, were completed with an overall score of 138. This is much lower than I would have expected for this processor under normal circumstances, but it’s not too surprising given the G20CB’s compact dimensions. The processor reached its maximum allowed temperature of 71 degrees almost instantly, meaning it wasn’t ever able to run at the full 4GHz it’s capable of, sticking to around 3.6GHz for most of the benchmarking process.

For comparison, the Mesh Elite Voyager Mini CS managed a score of 160, although admittedly this has a much bigger, more airflow-friendly chassis. Still, while it would be easy to forgive the G20CB’s performance on account of its tiny size, it’s nonetheless a waste of this processor’s potential as well as money down the drain for the consumer if it can never reach the speeds it’s designed for.

The graphics card, too, suffered under load. The G20CB is supplied with a 4GB Nvidia GeForce GTX 970, but prying open the chassis on our review unit revealed the card’s fan was partially obstructed by some supporting struts in the case, reducing its overall cooling potential. It showed in our benchmarks. A score of 114fps in Dirt Showdown on Ultra settings at 1,920×1,080 isn’t too far off the Mesh Elite’s 129fps in the same test, but the 35fps I saw in Metro: Last Light on Ultra with 4x SSAA was well short of the Elite’s 48fps.

The PC isn’t obnoxiously loud under load, but you’ll definitely know it’s there when you’re playing games. It gets pretty hot, too. If you’re going to place it under your TV, leave plenty of room behind and around it to allow the hot air to dissipate.

Storage comes from a 128GB HGST SSD, which managed a fairly unremarkable sequential read speed of 487MB/s in the AS SSD benchmark, while a score of 177MB/s in the write test was, again, mediocre. A 2TB hard disk is also supplied for bulk file storage. Upgradability, meanwhile, is very limited: this custom chassis is extremely difficult to work on and any upgrades will come at the expense of a pre-existing component.


Ultimately, the Asus RoG G20CB is a disappointing effort at a compact gaming PC, with high-spec components struggling to reach their potential thanks to cooling that doesn’t quite hit the mark. It’s one of my favourite PCs to look at, but sadly it falls wide of the mark in every other way. Even if it was able to keep up with the competition in terms of performance, its price is prohibitively high, making it a very hard PC to recommend.

We’d love to see a version with mid-range components instead, a Core i5 and GTX 960 card for example, these could hopefully shine to their full potential in what is a very desirable chassis and all for a more reasonable price. 

Core specs
ProcessorQuad-core 3.4Ghz Intel Core i7-6700
Processor socketLGA1151
Memory typeDDR4
Maximum memory32GB
MotherboardNot stated
Motherboard chipsetNot stated
Ports and expansion
Front USB ports2x USB3
Rear USB ports4x USB3, 2x USB2
Other portsNone
NetworkingGigabit Ethernet
Case typeMini-ITX
Case dimensions HxWxD108x358x340mm
PCI (free)Not stated
PCIe x1 (free)Not stated
PCIe x16 (free)Not stated
Serial ATA (free)Not stated
Memory slots (free)2 (0)
Drive bays 2 1/2″ (free)1 (0)
Drive bays 3 1/2″ (free)1 (0)
Drive bays 5 1/4″ (free)1 slimline (0)
Total storage128GB SSD, 2TB hard disk
Memory card readerNone
Optical drive typeDVD rewriter
Graphics card4GB Nvidia GeForce GTX 970
Graphics/video ports3x DisplayPort, 1x DVI, 1x HDMI
Sound cardRealtek HD Audio
Sound card outputs6x 3.5mm
Native resolutionN/A
Other hardware
KeyboardAsus U78K
MouseAsus U79M
Operating systemWindows 10 64-bit Home
Operating system restore optionWindows 10 restore
Buying information
WarrantyOne year RTB
Price including delivery (inc VAT)£1500
Price excluding monitor (inc VAT and delivery)N/A
Part CodeG20CB

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