Cooler Master MasterMouse MM520 review

A good mouse, but not excellent

TechRadar Verdict

Cooler Master’s MasterMouse MM520 holds up in serious video game testing, even if some of the build quality doesn’t hold up quite as well.


  • +

    Highly capable sensor

  • +

    Good switches

  • +

    Decent comfort


  • -

    Questionable build quality

  • -

    No better than the competition

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Cooler Master’s new MasterMouse MM520 is the claw-grip gaming mouse brother to the palm-grip MasterMouse MM530. The MM520 is billed as the successor to Cooler Master’s Spawn, and the similarities are evident. While Cooler Master touts the MM520 as a 6-button, high-DPI PC gaming mouse for real-time strategy games, it proves more versatile than Cooler Master has positioned it.

The MM520 costs $49 (£34, AU$59) just like the palm-grip MM530 does, which puts it in close competition with other serious gaming mice from Steelseries, like the $50 (£59, AU$99) Rival 310 and Sensei 310

This is no light competition for the Master Mouse MM520. The Sensei 310 received a perfect score in our review. So, let’s see how well the MM520 can stack up in the market of mid-range gaming mice.


The MM520 has the slightly more standout design of a claw-grip mouse, with a stepped right side that offers the ring finger its own support. The arch of the MM520 curves up from the back gently and then mostly flattens out toward the left and right click. The front even has a shape somewhat reminiscent of a Ferrari grill.

The left side of the MM520 is slotted for the thumb to rest comfortably and easily access the forward and back buttons. Unlike the MM530, the MM520 doesn’t include a rubber grip for your thumb. 

A honeycomb-patterned rubber strip is included on the pinky side, but it’s firm, shallow and a touch small. So, it doesn’t contribute greatly to a solid grasp, and for larger hands, it can require curling your pinky finger a bit extra.

Curiously and unfortunately, the placement of our pinky on the review unit over just a couple weeks began to dislodge the rubber strip ever so slightly. The two-year warranty may cover that though.

Our initial experiences of the MM520 don’t inspire much confidence. But, even with our fingers positioned somewhat awkwardly, we never fumble the MM520 in our lengthy playtests, and our pinkies never feel overly strained holding the mouse (though anyone not used to a claw-grip may feel more strain).

Aside from the glossy forward and back buttons the DPI switch and the scroll wheel, the MM520’s body is built with a coarse, matte black PBT plastic that adds a welcome extra bit of texture for the thumb and ring finger to hold. The plastic feels hardy, though, the MM520’s design results in some squishy areas with a bit of undesirable flex. 

Three-zone RGB lighting, supporting 16.7 million colors and variety of patterns, offers a bit of gamer aesthetic. An arc at the base of the mouse’s rear, the border around the Cooler Master logo and the scroll wheel all light up.

The main mouse buttons feel great. They’re satisfyingly clicky and consistent. The notched scroll wheel is grippy thanks to the soft rubber it’s made of, and it also clicks distinctly. Cooler Master’s choice of durable and responsive Omron switches is smart. 

The back and forward buttons aren’t quite as favorable, as both squish a tad too much. They’re at least consistent, clicking at around the same point regardless of where on the button we press.

Though it makes a somewhat cheap sounding clack when hit on the desk after quick movements, the MM520 has a comfortable heft to it at 101 grams or 135 grams with the cord weight factored in. The cable is long and light, not interfering with mouse movements, and its connection to the mouse is reinforced for an extra bit of robustness.


Even if the MM520 doesn’t shine design-wise (though with three-zone lighting, it does literally shine), it does a good job making up for that in the performance department. The MM520 uses Omron switches that prove reliable in our testing. They’re also long-lasting, rated for 20 million clicks.

Where the MM520 gets really spicy is in the PixArt 3360 sensor. It may not be a class-leading sensor, but it’s not far off. It supports sensitivities up to 12,000 counts-per-inch (CPI), and can track accurately even when it’s moving 250 inches-per-second (IPS) or at 50 times the acceleration of gravity. This combined with a polling rate up to 1,000Hz offers lag-free 1:1 input that holds up in our testing.

In our twitchy gameplay of Overwatch and Rainbow Six Siege, we never feel the slightest bit of hesitation from the MM520 to track our movements. If we miss a shot, that’s on us. Though the highest CPI settings aren’t the most useful on even a 1440p monitor, setting the MM520 between 2,000 and 3,000 CPI offers consistent tracking for big sweeping arm movements and subtle aiming with no noticeable pixel skipping. That said, the higher CPI settings have more to offer on higher-resolution settings.

Cooler Master’s software (which was a bit of a hunt to find), offers fairly deep customization. From this control panel, we can change the lighting scheme, remap all of the keys, create different profiles and change the four main CPI presets. It even has the option to turn on angle-snapping for anyone who wants this feature. The software can also assign secondary functions to each button you can toggle on and off.

All told, the performance of the MM520 is fantastic and a definite high point for this mouse, offering no excuses for poor gameplay.

Final verdict

There’s little ground to lodge any serious complaints against the MasterMouse MM520. It houses a killer sensor in a competent if not perfect body. If a low-cost, highly reliable gaming mouse is what you seek, the MM520 is up to the task.

The design of the MM520 leaves a little to be desired in terms of grip and hand feel, but it offers enough friction to hold it up for those brief gameplay moments when you need to lift the mouse and reposition it. Beyond some style choices and a little flex in spots, our only real issue is with the rubber grip coming loose, which we never really notice while gaming.

The MM520 is definitely a good mouse for the price. But, against competition like the Sensei 310, it fails to shine. Its claw-grip design with distinct zones for the ring and pinky fingers may offer a preferable grip for some, but the minor issues add up, preventing this from being a top pick.

Mark Knapp

Over the last several years, Mark has been tasked as a writer, an editor, and a manager, interacting with published content from all angles. He is intimately familiar with the editorial process from the inception of an article idea, through the iterative process, past publishing, and down the road into performance analysis.