Cooler Master Silencio S400 Micro ATX Case Review: Quietly Affordable

Editor's Choice

Tom's Hardware Verdict

The embodiment of the term "silence is golden,” Cooler Master’s Silencio S400 comes with an external drive optical drive bay and reversible front panel, ventilated and solid top panels, an SD card reader and sound damping material on all panels. The $90 / £90 asking price is also lower than most other cases in its class, leaving room in your budget for an extra intake fan if so desired.


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    Whisper quiet operation

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    Sleek design

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    Solid build quality

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    Reversible front door

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    SD card slot

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    5.25-inch ODD slot


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    Below-average thermal performance

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    No USB 3.1 Gen 2 Type-C

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    Front radiator support may require hard drive rack removal

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Features and Specifications

The current trend in PC cases seems to split between no-frills budget models and those with tempered glass panels and RGB lighting everywhere. But silence is golden for the enthusiast who places more emphasis on a quiet computing experience than flashy lights. If you’re okay with higher-than-average system temperatures and a lack of a USB Type-C port, the Cooler Master Silencio S400 could be just what you are looking for -- provided you don’t have or need a full-size motherboard.

Cooler Master Silencio S400 Specifications

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TypeMid-Tower ATX
Motherboard SupportMini-ITX, Micro-ATX
Dimensions (HxWxD)16.46 x 8.27 x 16.06 inches (418 x 210 x 408 mm)
Space Above Motherboard3 inches (76.2mm)
Card Length12.56 inches (319mm)
CPU Cooler Height6.57 inches (167mm)
Power Supply FormatATX
Weight15.5 lbs (7.03 kg)
External Bays1
Internal Bays4x 2.5-inch/3.5-inch
Card Slots7
Ports/Jacks2x USB 3.0Audio/mic combo jack
OtherSound damping materialReversible frontSD card slot
Front Fans2x 120/140mm (1 x 120mm included)
Rear Fans1 x 120mm (1 x 120mm included)
Top Fans✗ (Up to 2x 120 / 140mm)
Bottom Fans
Side Fans
Warranty1 year

Available only in black, the Cooler Master Silencio S400 is constructed of steel and plastic, measures 418 x 210 x 408 mm (16.5 x 8.3 x 16.1 inches), and weighs in at 15.5lbs (7kg). Priced at only $90 ( £80), it includes a one-year warranty on parts and labor.

The majority of top panel is covered by mounting locations for two 120 / 140mm fans. Cooler Master includes both a sound-damping vent cover that can be easily replaced by an included fan filter to allow air to flow when fans or all-in-one coolers are installed.

The front-right edge of the top panel has two USB 3.0 ports, a four-pole headphone and microphone combo jack, power and reset buttons and an SD card reader slot.

The front of the Silencio S400 features a large, reversible-swing steel-clad door that’s lined inside with a thick layer of sound-damping material. Behind the door you'll find a feature most case makers don't often deliver these days: a single 5.25-inch drive bay for an optical drive or a bay device. A large removable plastic mesh filter covers mounting locations for two more 120mm or 140mm fans.

Though the front panel is solid, Cooler Master designed the chassis with a large gap on both sides that allows cool air to be drawn through.

The Silencio’s steel side panels are lined with the same thick sound dampening material found behind the front panel and are held in place by captured thumbscrews. A different version of the S400 is available with a tempered-glass panel on the left side and steel on the right.

Four expansion slots with vented covers, an opening for a bottom-mounted PSU, and an exhaust-fan mount fitted with a 120mm fan are fairly standard for a chassis that supports up to Micro-ATX motherboards.. Adjustable screw holes let you position the fan higher or lower to fine-tune airflow or make room for system components.

A removable plastic mesh filter covers the PSU intake opening in the bottom of the case. Four round rubber-coated feet keep the case approximately one quarter of an inch off the floor to facilitate air intake to the power supply. In short, you probably don’t want to place a system built in this case on shag carpeting.

For the most part, the Cooler Master Silencio S400's fan filtration system does a good job in terms of its ability to prevent most dirt and dust particles from entering your system. As mentioned earlier, the included metal mesh filter on the top of the case (should you choose to use it) is attached by magnetic seals at the edge of the filter. The large plastic filter in the front of the chassis is easily accessible and removes in a matter of seconds. The bottom filter is the weak link in the filtration system. As with all chassis that use this type of filter, maintenance requires turning your entire system on its side to gain access.

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  • epicga
    Will be fan swap (moving the rear fan to the front of the chassis without adding third fan) a good option (lowering temperatures and maintaining low noise levels) also with good air (non liquid) CPU cooler?
  • Protonwrangler
    Looks like no airflow to the 3x 3.5" drives in the power supply area.