The ASUS ROG Phone II runs on a Snapdragon 855 Plus with 12GB of RAM, and ASUS' own internal engineering does something rarely seen on a smartphone, although it's commonplace in the PC gaming world.
With a squeeze of the sides – and a neat little onscreen animation if you're using ASUS' own Android theme – the processor is put into "X Mode", pushed to maximum frequency and optimised. It's not quite "overclocking" in the classic sense, but it's intended to grab every last processing cycle and deliver it to you for a premium gaming experience.
This can be seen in the difference between how the ASUS ROG Phone II benchmarks on a pure CPU level, and then how it performs with a gaming-specific benchmark.
First up, here's how the ASUS ROG Phone II compares using Geekbench 5's CPU test:
In regular mode the ASUS ROG Phone II lags behind its competition, but squeeze those sides and it most definitely perks up its performance. The ASUS ROG Phone II isn't a slouch when it comes to everyday Android tasks. Just like every other flagship phone released in 2019, you won't be left waiting to launch just about any app you could name. Also just like every other Android flagship, it's outpaced very handily by Apple's own in-house A-series processors.
However, when we throw a gaming benchmark at the ASUS ROG Phone II it shows its real strength, and not in a subtle way.
The ASUS ROG Phone II officially sold in Australia comes with 512GB of onboard storage, although ASUS does produce variants ranging down to 128GB and all the way up to 1TB of storage, so it pays to check what model you're getting if you buy one online. That's especially true because it's one of the rare breed of dual SIM phones that don't support storage expansion via sacrificing a SIM card slot.
Gaming is where the ASUS ROG Phone II really does shine, and that's true whether you use the Kunai Gamepad or not. The top and bottom right-hand sides of the ASUS ROG Phone II feature small etched sections, but they're not just there for visual flair. They're touch sensitive buttons that ASUS calls "Air Triggers", and you can configure them to tap on a specific area of the display. The idea here is that in landscape mode, you use them like you'd use the triggers on a gamepad, once you've configured their use with ASUS' inbuilt games launcher.
It's the same story with the Kunai gamepad, whether you're using the controller paired over Bluetooth or in the case with the individual legally-distinctly-not-joycons-but-they-are slotted into the sides. What this means is that you can get a console-like experience from the ASUS ROG Phone II, but only after you've configured each game of choice to match its on-screen tap or slide areas.
It can be something of a painstaking process, and the entire time I was testing out the ASUS ROG Phone II, I was reminded that just about any Android phone can pair with a PlayStation or Xbox controller with relatively little fuss, and a lot of Android games are built with those controllers in mind, so there's no configuration at all to be done. ASUS is to be commended for the customisability of its approach – but sometimes you just want to play a game, you know?
It's pain for gain, especially if you throw in a game with inbuilt 120Hz compatibility. ASUS has a maintained list of compatible games on its website, with, at the time of writing, around 170 Android games with 120Hz support.
Switching from games as diverse as Mortal Kombat to Minecraft on the ASUS ROG Phone II and then on the Samsung Galaxy Note10+, that difference in refresh rate was absolutely noticeable. It doesn't mean that your regular phone is playing those games like rubbish – they're just not at their peak best.