The race among gaming monitors for the highest refresh rate is well and truly on. The Asus ROG Swift PG258Q is the second 240Hz monitor to launch this year after the BenQ Zowie XL2540.

These 240Hz monitors can render every pixel on their screens at up to 240 times per second. They are desired by gamers because images look smoother and more fluid, especially when you are panning or shifting the camera in a game. They make standard 60Hz monitors look juddery in comparison.

Going from a 60Hz display to a 120Hz screen is an obvious improvement. But, in my testing, I could not distinguish between 120Hz and 240Hz reliably - both settings look fluid and smooth to me.

I am also not convinced that the refresh-rate boost makes up for the fact that both Asus and BenQ had to use twisted nematic (TN) panels instead of in-plane switching (IPS) because only TN screens are currently able to reach such high refresh rates.

Granted, these TN panels are best-in-class for its type, but they still have slightly limited viewing angles, compared with IPS ones. Colours also look more washed out. In short, I would not recommend this monitor for a non-gamer.

High-refresh-rate monitors also necessitate a powerful graphics card to produce sufficient frame rates for the monitor.

Otherwise, you would have to lower the screen resolution or disable in-game visual effects.

Unsurprisingly, the 25-inch Swift comes with a modest 1,920 x 1,080-pixel screen resolution. Even then, gaming PCs may still struggle to achieve over 240 frames per second in the latest games without tweaking the settings.

The Swift does have an advantage over its BenQ Zowie rival. It supports Nvidia's G-Sync technology that synchronises the game's frame rates to the monitor's for a stutter-free experience.

This feature, however, comes at a price. Nvidia charges a fee for the proprietary hardware chip required for G-Sync. It also works only with Nvidia graphics cards. This partially explains why the BenQ costs $799, compared with the $1,099 Swift.

In addition, G-Sync and the 240Hz refresh-rate option are available only via the DisplayPort on the Swift.

It has all the bells and whistles of an Asus high-end gaming monitor. Unfortunately, these include a gimmicky light projection feature at the base of the stand that projects the ROG logo on your desk. Slightly more useful are the gaming overlays, like a crosshair, a timer and a frame-rate counter.

Most relevant to gamers is an Ultra Low Motion Blur feature that reduces ghosting when objects on screen are moving rapidly.

I like the 5-way joystick at the back of the monitor. It makes navigating the monitor's onscreen display settings (OSD) a breeze.

With its thin bezel, you can place two or even three of these monitors side by side without having the eyesore of a thick bezel. The monitor itself can swivel left or right by up to 50 degrees. It can also pivot 90 degrees to go from landscape to portrait orientation, which is unusual for a gaming monitor.

As a gaming monitor, the Swift is peerless in terms of features and performance. But there are obvious drawbacks because of its TN panel, especially for non-gaming usage.

It is also very pricey.

Vincent Chang

•Verdict: If you do not need G-Sync, the BenQ Zowie XL2540 seems like a better deal. But for the well-heeled gamer with a capable PC and with the eyes to detect 240 frames per second, the Swift has no rivals.