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Cooler Master MasterLiquid ML240R RGB review: High performance and outstanding quietness

Our Rating :
£94.49 from
Price when reviewed : £101
inc VAT

It has highly customisable lighting, but the quiet cooling is what really shines


  • 16.7 million colours to choose from
  • Seriously good cooling performance
  • Close to silent


  • Tricky to install

The last time we reviewed a Cooler Master AIO watercooler was way back in 2016, with the MasterLiquid Pro 240 putting in a decent if unremarkable showing.

The MasterLiquid ML240R RGB might seem a fairly radical departure, but we’re not looking at sweeping changes: the pump has been upgraded but still uses Cooler Master’s dual-chamber structure, and those clear plastic fans have the same maximum speeds and air pressure as the Pro 240’s: 2,000rpm and 2.34 mmH2O respectively. The biggest change that this cooler (and its little brother, the 120mm ML120R RGB) bring to bear is, undoubtedly, addressable RGB lighting, which glows from the pump as well as both fans.

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That’s a whole 16.7 million colours for you to mix and match, or combine with various transition effects, and it works together with Asus Aura Sync, ASRock Polychrome Sync and MSI Mystic Light Sync, so if you have a compatible motherboard or graphics card, you can set the same colours and effects to glow from the ML240R RGB simultaneously.

Smartly, Cooler Master has included an RGB controller unit, so you don’t need any dedicated RGB headers on your motherboards to make this cooler shine: just a spare USB header and SATA power cable to give it some juice. The controller also includes some buttons for switching between colours and effects, which could be a handy alternative to software control unless you’re not easily able to open up your PC’s case.

Cooler Master MasterLiquid ML240R RGB review: Installation

Here’s the catch, though: all this RGB connectivity makes installation a messy process. Since both 120mm fans and the pump have separate cables for connecting to the motherboard and to the controller, you’re already dealing with twice as many wires as almost any other 240mm AIO watercooler, and that’s before you factor in the USB and SATA cables. You’ll also need to find space for the controller itself, ideally where it can’t bump into any other internal components.

All that said, there are a few touches that make setting up the cooler less stressful. For instance, the two braided tubes are far more flexible than they were on the Pro 240, which meant we could fold the whole unit into our test PC much easier. We also appreciated how the mounting kit for Intel sockets merely required a bit of screwdriver work; there’s nothing like the horribly difficult push-together pump brackets of the Be Quiet! Silent Loop 360mm.

The system for attaching the pump to AMD sockets is also much better than the fiddly clips used by most coolers: you can extend the length of the clasps by loosening their thumbscrews, hook them over the mounting plate, then turn the thumbscrews to tighten.

There’s no pre-applied thermal paste, but the little bundled tube (for you to apply yourself) is the next best thing. As with previous CPU cooler reviews, we installed the ML240R RGB on top of a quad-core Intel Core i7-4770k, testing at its stock speed of 3.5GHz as well as with an overclock to 3.9GHz.

Cooler Master MasterLiquid ML240R RGB review: Performance

At stock speeds, the ML240R RGB acquitted itself well, with the CPU idling at 29-33°C. Under the intense load of our 4K benchmarks, this rose to 51-54°C with a peak temperature of 56°C, and while running Metro: Last Light Redux (where our GTX 1060 graphics card did most of the work), it generally hung around the 38°C mark with a brief peak of 46°C.

That’s a big improvement over Intel’s stock air cooler, as you’d expect, and temperatures barely rose once we applied the 3.9GHz overclock. Idle temperatures stayed nice and low, between 30°C and 36°C, and even during the most punishing parts of our 4K benchmarks, the ML240R RGB managed to keep the processor around 57-60°C. The very highest temperature we recorded was 61°C, miles off the Core i7-4770K’s limit.

The post-overclock differences were even smaller in Metro, with temperatures rarely straying beyond the 40-42°C range. At one point the CPU hit 48°C but again, these are seriously good performances, not to mention improvements on the Pro 240.

Indeed, performance-wise this cooler is on equal terms with two of the chilliest AIO units we’ve used, the Silent Loop 360mm and the NZXT Kraken X62. The Be Quiet model keeps peak temperatures lower by a few degrees, but there’s not much in it.

Cooler Master MasterLiquid ML240R RGB review: Verdict

What’s even more impressive is how quiet the whole thing is. We never heard any water rushing sounds on startup, like our Pro 240 sometimes makes, and the fans were so close to silent that there wasn’t a single point – even during the overclocked 4K benchmark run – that they became louder than the 120mm exhaust fan in our case, or the blower cooler on the GTX 1060.

As such, it’s not fancy flashing lights that make the ML240R RGB so good: it’s the high performance and outstanding quietness. Truth be told we still slightly prefer the classy looks and simpler installation of the Kraken X62, but for those with more colourful tastes and a willingness to do some extra cable tidying, this is everything you could ask for.

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