Performance Analysis

It’s hard to argue with those temperature results, and the high-airflow credentials of the Cooler Master NR400 are nicely confirmed. Both CPU and GPU were running about as cool as they would on an open test bench, and the NR400 places top or joint-top for both measurements.

The exhaust fan is positioned very close to the CPU cooler, thus extracting hot air quickly and efficiently, and the roof allows for further natural ventilation. Meanwhile, the unobstructed front fan delivers plenty of cool air directly to the GPU’s intake fan.

Neither case fan is particularly loud, but the NR400 also isn’t good at containing noise. That said, the excellent airflow will prevent fans on coolers from ramping up too loudly, so noise shouldn’t be too big an issue for most.

Conclusion

The Cooler Master MasterBox NR400 is a great little chassis overall. There are always sacrifices at £60, but Cooler Master does well in not having them be major ones. The PSU dust filter is a bit rubbish, and the steel does feel thin and cheap in more than one place, but this is more than made up for in other areas.

Building a system is easy, and the chassis’ size belies its impressive level of hardware support including storage, large GPUs, and some water-cooling. The various spaces are flexible to cater to users that have different priorities, and Cooler Master also receives top marks for out-of-box thermal performance; that mesh front panel is a real winner.

Undercutting the Define Mini C TG from Fractal Design by £20 is a smart move, as this is also a case to be reckoned with. It has the edge on build quality and cable management, but Cooler Master has more flexibility and even better airflow. As such, the NR400 slots neatly into the micro-ATX tower market and is well worth shortlisting if it’s the sort of case you’re after.