NZXT Source S340 Mid Tower

Table of Contents

For a US$70 tower case, the NZXT S340 is surprisingly well built, attractive, and usable. It offers a level of refinement not usually available at this price-point.

July 28, 2015 by Lawrence Lee

NZXT Source S340
ATX Tower Case

NZXT has cultivated a reputation for producing tower cases with a high degree of fit and finish and a heavy emphasis on usability. Their “Source” series of budget cases aren’t as upscale as the rest of their lineup, offering the cash-strapped a taste of the NZXT experience at a more palatable price. The Source S340 is perhaps their most intriguing SKU, straddling the border between flimsy US$50 enclosures and more versatile and feature-rich US$100+ models. The question is whether it’s the former masquerading as the latter or the other way around.

The Source S340 (white).

Like many NZXT cases, the S340 is available in a variety of colors. Our sample is the white model but it also comes in all black, and in black with red or blue trim/LEDs. The most interesting physical aspect is the completely solid front reminiscent of the H440. While the panel is made of plastic, it has a steel face that matches the sides, giving it a plain but elegant look. The main intake vent is just a wide and long gap running from the top of the bezel to the bottom. The lack of external drive bays will undoubtedly disappoint users still bound to optical media and those who prefer the ability to add a panel for controlling fans or reading memory cards, etc. The sad fact is the wind is shifting away from this paradigm — in this day and age, few people need this versatility, and the S340 is an affordable chassis designed for the masses.

That’s also probably why storage support has been cut back to just two 2.5 inch and three 3.5 inch drives. This should be a boon to performance as all the drive bays, which usually impede airflow from reaching the critical components, have been dispensed with. Instead of the 6+ fan placements in a typical modern tower, the S340 provides just four with two 120 mm fans included. AIO cooling units can be utilized but they can only be installed at the front or rear as the top offers just enough space for a fan and nothing else. Limiting these features also allows for a slimmed down body, with the S340 measuring about 17.5 inches tall and 17.0 inches deep. In terms of volume, it comes in under 40 Liters — it’s the smallest ATX tower I can recall handling in some time.



Our sample shipped in a plain unadorned box but the retail versions are better decorated. Included with the case is a decent assembly guide and a box containing a few zip-ties and the necessary screws separated and labeled for convenience. To make standoff insertion easier, they’ve also provided a nut-driver.

Specifications: NZXT Source S340
(from the
product web page
Model Number CA-S340W-W1 (White)
CA-S340W-B1 (Black)
Drive Bays External 5.25″: 0
Internal 3.5″: 2+1
Internal 2.5″: 2
Cooling System Front: 2x 140/2x120mm
Top: 1x 140/120mm (1 x 120mm FN V2 Fans Included)
Rear: 1x 120mm (1 x 120mm FN V2 Fan Included)
Filters Front (Included)
Bottom Rear(Included)
Radiator Support Front 2 x 140 or 2 x 120mm
Rear 1 x 120mm
Clearance GPU Clearance With Radiator: 334mm
GPU Clearance Without Radiator: 364mm
CPU Cooler: 161mm
Cable Management: Lowest Point – 17mm; Highest Point 168mm
Dimensions 200mm x 445mm x 432mm
Material SECC Steel, ABS Plastic
Motherboard Support Mini-ITX, MicroATX, ATX
Expansion Slots 7
External Electronics 1 x Audio/Mic
2x USB 3.0
Product Weight 7.05 kg
UPC 815671012111 (White)
815671012128 (Black)
815671012371 (Black/Red)
815671012364 (Black/Blue)
USB 3.0 Ports 2
Warranty 2 Years


The NZXT S340 has a steel frame and a plastic top/front but the front bezel also has a sheet of steel armor to match the side panels. The whole package weighs 7.05 kg or 15.5 lb and measures 44.5 x 20.0 x 43.2 cm or 17.5 x 7.9 x 17.0 inches (H x W x D), not including the feet. Its total volume is a mere 38.4 Liters — with minimal drive support, it’s noticeably more compact than most ATX cases.

The gap behind the front bezel measures 23 mm across and runs all the way down, giving the front fan placements plenty of breathing room. The control panel is at the very top of the case, offering audio and USB 3.0 ports. The power button is located on the right with muted white LED lighting around the perimeter to complement the small hard drive LED on the opposite side.

While there is room for an extra fan slot on the ceiling, NZXT opted to for just the one 120/140 mm fan installation at the top. The S340 ships with two 120 mm FN V2 fans.

The rear of the case is home to the second fan, installed in a fan mount with a more restrictive than usual, with noticeably smaller holes than previous NZXT cases I’ve examined. The power supply at the bottom is installed through the back using the included frame. Also note the non-reusable expansion slot covers.

The S340 is propped up on statuesque 28 mm tall feet. Towards the front are holes for mounting a 3.5 inch drive on the case floor. The rear is home to the power supply intake vent, covered with an exposed fine mesh filter.

For a US$70 case, the side panels are a surprising 0.9 mm thick. They fit fairly snugly against the chassis and are held on with captive thumbscrews.


The S340 has a typical layout for an ATX tower with a couple of twists. A tunnel at the bottom of the case segregates the power supply from the rest of the system, and in doing so, helps hide all the thick ugly power cables. 2.5 inch drives have a pair of dedicated trays secured to the top of this tunnel, while up to three 3.5 inch drives can be installed underneath it. With no visible drive cages at the front, the intake vents are completely unimpeded which should be a boon for performance.

The front panel takes some force to pry off. Behind it is a large magnetic dust filter covering the front 120/140 mm fan locations. The filter material is the same as underneath the power supply, but this one has a proper plastic frame. The mesh is quite thin, allowing air to more easily pass through compared to most cases.

Without any drive cages next to the motherboard tray, the interior is rather spacious. The power supply tunnel helps keep the guts of the case look clean.

Most modern towers are outfitted with as many fan placements as physically possible but the S340 offers only four. This isn’t usually an issue for me, but it should be noted that if you want to use a 240/280 mm radiator, it can only be mounted at the front which is better suited for intake fans.

A single fan radiator can be installed at the rear but the top fan location is too close to the edge of the motherboard tray. The two included fans are 1200 RPM models with 3-pin connectors (4-pin molex adapters included).

Unlike the case exterior, the interior doesn’t feel as strong because it’s thinner and the motherboard tray does not extend all the way the bottom. Cable management however should be excellent as there are many strategically located hoops for pinning down wires. Also, the white bracket next the motherboard tray edge is depressed, giving a bit more room to thick cables in this area.

Oddly, the two-bay 3.5 inch drive cage hanging underneath the tunnel doesn’t extend all the way to the bottom. A third drive can secured to the case floor from underneath.


With no traditional front drive cages getting in the way, assembling a system inside the S340 is a breeze. While there are no tool-less install mechanisms, thumbscrews are provided to mount the expansion slots and drives. There’s also ample space behind the motherboard for tucking away excess cabling.

Our test system fully assembled. The top fan has been moved to the front to better cool our Asus GTX 980 (our system’s biggest heat/noise generator).

The width of the case is somewhat of a concern. Our Scythe Mugen Max is 16.0 cm tall and while there is 4 mm of clearance between it and the side panel, but the edge of the window juts inward by 4 mm, so the two touch. This makes vibration from the fan actually audible, so during testing, a small piece of foam was placed on top of the heatsink to steady it. A narrower 120 mm fan heatsink probably won’t have this issue.

At the back, cables are dealt with fairly efficiently.

There is only 16 mm of space directly behind the motherboard tray, but toward the front, where most of the thicker cables end up, the clearance is a substantial 20~38 mm greater.

If you opt to use the drive cage, three screws can be used on the left side but only one on the right side. The fit is rather loose as the drive slides in without any resistance.


System Configuration:

Test system device listing.

Measurement and Analysis Tools

  • Prime95
    processor stress software.
  • FurMark
    stability test to stress the integrated GPU.
  • Asus GPU Tweak to monitor GPU temperatures and adjust fan speeds.
  • SpeedFan
    to monitor system temperatures and adjust system fan speeds.
  • Extech 380803 AC power analyzer / data logger for measuring AC system
  • PC-based spectrum analyzer:
    SpectraPlus with ACO Pacific mic and M-Audio digitalaudio interfaces.
  • Anechoic chamber
    with ambient level of 11 dBA or lower

Testing Procedures

The system is placed on load using Prime95 (large FFTs setting) and FurMark, an OpenGL
benchmarking and stability testing utility. This puts more demand on the CPU and GPU than any real life application. Throughout testing, system temperatures, noise levels, and power consumption are recorded. During the load test, the system and GPU fans speeds are adjusted to various levels in an attempt to find an optimal balance between cooling and noise while maintaining a GPU temperature of 80°C (assuming an ambient temperature of 22°C).

Baseline Noise

For our baseline noise tests, the system is left idle, the CPU fan is set to its minimum speed under PWM control, and the GPU fans are off by default. The system fans are connected to controllable fan headers and are set to a variety of speeds using SpeedFan. This gives us a good idea of what the stock fans sound like at different speeds with minimal interference from other sources.

Our test drive, slightly modified.

Upon turning on the system, I was greeted by the ominous sound of hard drive vibration. The drive doesn’t fit well in the cage and the thumbscrews, no matter how well tightened, are insufficient to keep vibration effects at bay. Mounting the drive at the very bottom of the case proved to be even louder. The only way I could think of to steady the drive was to tape foam strips to the sides. This made it much more difficult to slide the drive into place but the extra tension settled things down considerably.

Another modification to the front panel.

I also found that pushing against the front bezel helped mitigate some of the tremors caused by the hard drive. While it seemed failry securely attached to the frame, shoving a dense foam block into the gap made a measurable difference of 1~2 dB. For better aesthetics, the block can be pushed down into the hole until it’s no longer visible.

Baseline Noise Level
(Idle, CPU fan at 400 RPM, GPU fans off)
Fan Speed Setting
Avg. Fan Speed
SPL @1m
16~17 dBA
620 RPM
18 dBA
910 RPM
21 dBA
1120 RPM
25~26 dBA
1290 RPM
29 dBA
Measuring mic positioned 1m at diagonal angle left/front
of case.
Ambient noise level: 10~11 dBA@1m.

Though the modifications did help significantly, the baseline noise level with the CPU fan at minimum speed and everything else off is 16~17 dBA@1m, slightly higher than usual. The included fans start to contribute extra noise starting at near 40% speed (620 RPM). They stay reasonably quiet up to around 60% but get considerably louder past this point even with minor increases in RPM.

The subjective quality of the fans is excellent. The FN V2 is one of my favorite 120 mm case fans and it’s not hard to see/hear why. They have a supremely smooth acoustics with a mostly broadband profile. Most of the noise they add to the system are in the midrange, between 200 and 1000 Hz, with barely a hint of tonality, even at speeds of 80% and higher. If you care about how the system sounds, you’d be hard pressed to find a superior stock case fan.


System Measurements: CPU + GPU Load,
80°C Target GPU Temp
Avg. System
Fan Speed
620 RPM
910 RPM
1000 RPM (70%)
1120 RPM (80%)
GPU Fan Speed*
1380 RPM
1170 RPM
1170 RPM
1120 RPM
CPU Temp
MB Temp
System Power (AC)
27 dBA
25 dBA
25~26 dBA
26~27 dBA
*set as low as possible to maintain target GPU temperature on load.
CPU fan at 60% (800 RPM).
Ambient temperature: 24°C.

For our system configuration, the stock fans running at 60% (910 RPM) produces the quietest result, 25 dBA@1m with the GPU fans at 43% speed. Increasing the speed of the system fans further results in only very minor differences in CPU and motherboard temperature. At 80% speed, GPU cooling does not improve enough to allow the video card fans to slow down, while at 100%, the case fans drown everything out.


The noise emitted doesn’t differ much from what was produced during the baseline tests. The CPU and GPU fans generate a poorer acoustics than the stock case fans, but they don’t spin fast enough to change the overall sound of the machine. At the machine’s sweet spot, the noise output is about as pleasant as 25 dBA@1m can sound.


Case Comparison: System Measurements
(CPU + GPU Load, 80°C GPU Temp at 22°C Ambient)
Fractal Define S
SilverStone KL05B-Q
Zalman Z11 Neo
Antec P100
Avg. System Fan Speed
630 RPM
(2 x 80%)
840 RPM
(2* x 60%)
960 RPM
(3 x 70%)
910 RPM
(2 x 60%)
980 RPM
(2 x 80%)
GPU Fan Speed
1120 RPM
1070 RPM
1180 RPM
1170 RPM
1530 RPM
CPU Temp
MB Temp
23 dBA
24 dBA
25 dBA
25 dBA
25~26 dBA
Street Price (USD)
*one fan added.

Compared to previously tested sub-$100 cases, the S340 is a middling performer, about on par with the Zalman Z11 Neo and Antec P100. This result is disappointing as its fairly open intake airflow design is not dissimilar to that of the Define S, which leads this pack of budget competitors.

The only thing I can think of that could be responsible for this discrepancy is the limited exhaust ports. The fan grill at the back is noticeably more restrictive than most cases and there’s only a single fan vent at the top. Almost all modern towers offer two fan mounts on the ceiling and this undoubtedly helps hot air escape the case more easily. This could have been enough to offset any gains from having unrestricted airflow coming in through the front panel.


These recordings were made with a high resolution, lab quality, digital recording
system inside SPCR’s own 11 dBA ambient anechoic chamber, then converted to
LAME 128kbps encoded MP3s. We’ve listened long and hard to ensure there is no
audible degradation from the original WAV files to these MP3s. They represent
a quick snapshot of what we heard during the review.

Each recording starts with ambient noise, then 5~10 second segments of product
at various states. For the most realistic results,
set the volume so that the starting ambient level is just barely audible, then
don’t change the volume setting again while comparing all the sound files.


Given the similarities with the Fractal Define S, I was expected great things from the NZXT S340. Without drive cages in the way, the two cases have effectively unimpeded front intakes. The Define S uses traditional vents along the sides of the bezel while the S340 opts for a large gap running down the entire front panel. Sadly, the S340 runs slightly warmer and moderately louder under our testing parameters. The difference may be due to S340’s more restrictive exhaust system or the Define S’ larger, potentially more efficient 140 mm fans (or a combination of both). Compared to other sub-$100 cases, the S340 is not a poor performer, it’s just not a standout.

From a silencing perspective, the S340 takes some user intervention to cut down on noise. Fortunately, the fans don’t have to be replaced as the stock models sound absolutely sublime. Hard drive vibration is the biggest issue as the drive cage isn’t particularly well secured and 3.5 inch drives fit too loosely inside. Adding some damping material to the sides of the drives helps considerably as does bracing the intake gap of the front bezel.

The S340’s aesthetics are simple yet classy and the external build quality is more than you can expect from a budget tower. Furthermore, minimal effort is required to make the interior look clean through the side window — the internal design hides the less attractive portions of the case and this is complemented by good cable management. The size of the case is also refreshing, not overly large like most models these days. Cutting back on drive support allowed NZXT to reign in its dimensions, though I wish they had made it slightly wider on the left side for better CPU cooler support. I hope one day they take it a step further and produce a microATX variant as the ATX form factor itself is oversized for the majority of PC users.

The S340 has its fair share of flaws but as it sells for only US$70, they can be mostly forgiven. It punches above its weight class, looking and feeling like a pricier model. That is about as much as you can ask for from a budget case.

Our thanks to NZXT
for the Source S340 case sample.

The NZXT Source S340 is recommended by SPCR

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Fractal Design Define S Tower Case

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this article in the SPCR Forums.

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