Lian Li PC-B25S Mid-tower Aluminum Case

Table of Contents

There’s something about a handsome brushed aluminum case that everyone admires. The Lian Li PC-B25S mid-tower case has that aluminum panache, and a whole lot of features to go along with it. Does it have the cool and quiet performance to stand next to SPCR’s recommended cases for silent computing?

Lian Li PC-B25S All-Aluminum Mid-Tower Case

January 14, 2011 by Mike Chin

Product
Lian Li PC-B25S
Mid Tower PC Case
Manufacturer
Street Price
US$170~245

The PC-B25S is a recent addition to Lian Li’s extensive aluminum PC tower case lineup. Along with Cooler Master and Silverstone, Lian Li has been long associated with aluminum PC cases, especially high end models. The PC-B25S is not at the top of the Lian Li catalog, but it is not at the bottom, either. Any case that carries a >$200 price tag certainly has to go beyond the essentials. Mid Tower, it is called, but the generic description belies the number of special features in this case. As the photo below confirms, Silent is a strongly emphasized benefit on the full color carton, along with Noise Reduction Foam.

So we know that the case is pre-lined with some type of acoustic foam on inside panels, but is there more? Yes, a lot more. The PC-B25S has an enormous number of extras and features aimed at noise-conscious PC users. Our review will show that some of these features are ingenious and very well executed, some are smart but don’t work quite as intended, and still others don’t even make any sense or appear to be absurd errors. There’s more than a little sense of being rushed, of a product built with a check list rather than a complete integrated system perspective. Still, it is not without charm, there is some great workmanship and materials, and it works better than you might expect from the previous words in this paragraph.


Low noise is emphasized in the PC-B25S packaging.

The PC-B25S is attractively "skinned" in black brushed aluminum around good "bones". The case at its
tallest point is nearly 21.5", with a depth of 19.25" and width of 8.25", which puts it on the larger side of "mid tower" cases, along with the Antec P183, the Fractal Design Define R2, and the Silverstone Fortress FT01. Its top and front edges are complexly bevelled, but the entire case is formed of aluminum, with virtually no plastics.


Metallic silver feet and the blue ring in front (which lights up when the system is powered on) are the only exceptions to the brushed black anodized aluminum on four sides.

As you can guess from the profile of the top panel, there is a fan atop near the back panel, in addition to a back panel exhaust fan. Before we go further, here are the complete specifications from Lian Li.

Specifications: Lian Li PC-B25S
(from the
product web page
)
Model PC-B25S
Case Type Mid Tower Chassis
Dimensions (W) 210 x (H) 545 x (D) 497mm
57 liters volume (excluding added 25mm height of aluminum feet)
Front bezel Material Aluminum
Color Black
Side Panel Aluminum with noise reduction foam
Body Material Aluminum
Net Weight 7.2KG
5.25" drive bay (External) 3
3.5" drive bay (External) 1 (use 5.25 to 3.5-inch converter)
3.5" drive bay (Internal) 6
Expansion Slot 8
Motherboard ATX / Micro ATX
System Fan (Front) 120mm Fan x2
System Fan (Top) 140mm Fan x1
System Fan (Rear) 120mm Fan x1
I/O Ports 2x USB3.0, e-SATA,HD Audio
Maximum Video Card Size 285mm

OUTSIDE DETAILS

The actual volume of the PC-B25S is around 55~56 liters, but the raised triangular cross-section part of the top panel, and the 2.5 cm tall silver puck feet make it seem a bit bigger.


A view of the front
and top, with blue ring light on. Note that there are no air vents in the front, but the bezel’s side edge is liberally vented all around with many small slots, much like in the Antec P180 series cases.

The rear panel features a 120mm fan, ports for watercooling pipes. The PSU mounts at the bottom.

Beneath the raised section is a 140mm fan, with a vent on the back end.


The top bezel pops off easily with a little tug at the front. It is friction fit on four plastic points. The inside of the removable top panel is lined with thin foam, presumably to reduce the audibility of the fan. Note the unnecessary dust filter on the fan. This is an exhaust fan — the air blown out of the case hardly need to be filtered. You might be able to see a tiny slider switch behind the fan. This is a 3-speed switch for a built in fan controller.

The underside is equipped with intake vents reminiscent of a washer board, and removable dust filters on the outside. These are primarily for the PSU.

INTERIOR

Two thumbscrews need to be removed to gain access to the left side of the case. The interior panels (and the bottom and back) are not anodized. The side panels are lined with foam.


There are protective grills over the top and back panel fans. Both side panels are lined with foam.


Detail of aluminum disc feet.

The aluminum feet are about an inch tall, the tallest we’ve seen for any case. It is a good height for a case that puts the PSU on the bottom, with an intake fan on the bottom. The extra clearance is needed for the PSU fan to breathe adequately. The feet are unusual enough that one was removed for close examination. It turns out they are made from two parts: A solid machined aluminum disc, and a matching aluminum-plastic-rubber disc that fits perfectly into the top disc, all held together with a machine screw and washer, screwed into a properly tapped hole on the bottom panel. These feet stand as a paradigm for the entire case: Attention to detail with excellent execution and fine materials (the correct height for the feet, good sizing for balance, great machining, nice non-slip rubber bottom surface), yet unnecessary complexity — if you go to the trouble of machining a disc from a solid piece of aluminum, why not just make one the right size to be a foot by itself? Instead, they made it in two parts. Perhaps the composite half was the original foot design, and then someone decided it was not tall enough, so the additional all-aluminum disc was added, rather than discard all the already produced original feet.


The foam glued to the inside of the side panels is thin and not very dense. It is not going to absorb much internal reflections except at higher frequencies, but it might help reduce sympathetic vibration (transferred from hard drives and fans) in the panel itself.

In a small carton inside the case, there were bags of screws of various types and sizes, a two-part noise baffle or deflector for the back panel fan, a piece of adhesive backed foam to line this baffle, a Y-adapter to use the top panel USB 3.0 ports with a USB 2.0 internal motherboard header, and a locking clamp mount for the PSU. All this is atop a multilingual, photo-illustrated instruction sheet.

MORE INTERIOR

Working inside the PC-B25S is safe, as panel edges are rolled to prevent cuts
and scratches, and the front fan and drive cages can be removed without tools.
Cable management is well thought out for the most part. The overall impression is one of high quality materials and good execution… with some odd exceptions, as noted in the photo captions below.


Note liberal use of thumbscrews, adapters for fans to run off different types of power connectors, and lots of holes for hiding cables easily. All the fans have native 3-pin connectors for motherboard fan headers, with adapters to use directly off 4-pin PSU outputs.

The motherboard tray has multiple holes all around the perimeter for cable management, as well as a large hole behind the CPU area for heatsinks that require access to the underside of the motherboard. The motherboard tray extends only to about the top of the PSU, leaving an open gap of about 3" to the bottom panel. This is useful for cable management, too. The PSU does not sit directly on the bottom panel, but on raised and soft-damped sleds, which provides yet more breathing space for the PSU’s intake fan.

The case has a pair of front USB 3.0 ports, but as most motherboards
still do not have internal USB 3.0 headers, external cables are provided. They need to be routed through and plugged into the back panel ports of the motherboard. An internal
USB 2 header adapter is included, but there is no adapter for USB 3 headers, which are now appearing on the latest motherboards. Inexplicably, a stamped metal grill is used on the inside of the 120mm back panel fan, instead of the more common and less restrictive (for airflow) wire grill. There is no grill on the outside of this fan — again, this seems an odd choice. Isn’t there more possibility of interruption to the fan blades on the outside of the case? (Yes, we know that wires on the inside of cases sometimes rub against fan blades and make noise or even get cut by them, but this rarely happens with experienced builders — few newbie builders would use a >$200 case.)


Up in the top back corner, tucked between the back and top panel fans, is a speed controller for three fans. The switch is on the top panel, behind the top fan. There is a position on the PCB for a fourth fan header, which would have made sense since the case has four fans, but it has been left empty. There are no Y-adapters for joining two fan leads, and the front fan leads are not long enough to reach this fan controller.


The front bezel pops off easily the same way as the top panel, and it too, is lined with foam on the inside. A 2-conductor cable for the blue ring light feeds through a hole neatly positioned on one side. When this cable is not connected to the power supply (via another 2-pin to 4-pin adapter), the front bezel can be pulled away altogether.

Another oddity is the washer-board style vented cover for the two intake 120mm fans mounted in front. The front bezel already blocks the fans from having a direct sound path out, and it is already lined with foam on the inside. So why further deflect the sound path at the cost of additional airflow restriction? On top of this, remove the vented cover, and we find…



…yet more airflow restriction in the form of two dust filters over the fans. (Bottom dust filer removed.) We chose to keep the dust filers on and leave off the vented cover.

While we are on the topic of fans, note the way the above fan is mounted. There is a special rubber grommet that goes on the bolts. This grommet has a groove that fits the thickness of the aluminum panel. The holes for the fan are set up so that it is a slide-locking mount. Position the fan so that the screws fit into the big holes, then slide the whole fan down a bit so that the rubber grommets fit into the edges of the smaller holes which overlap the bigger holes. It’s much easier to show than to tell. Please see the animated GIF below. (If the animation has stopped, just refresh your browser window.)



It’s a clever if elaborate way to soft mount a fan. This is the same way that all the fans are mounted… with one exception: The back panel fan. Please see the photo below.


A similar overlapping bigger/smaller hole are used here for the fan screws and grommets… but there are two mirror image pairs, rather than the series pairs needed, which means the insert, slide and lock system cannot work. Did a designer fall asleep at his workstation? Is there some other reason for the above design that we cannot fathom? Whatever. The only way this fan can be installed is to insert the grommets in the panel first, then slide the bolts through grommets and screw it into the holes in the fan. In other words, conventionally. Yet, a still different type of hole was machined in the back panel for the mounting of this fan.


Tool-free clamp mounting for add-in slot cards works very well, providing good support even for heavy video cards. All the slot covers are vented.


The drive cage is quite sturdy, and also secures to the chassis securely, with two thumbscrews on top, one on the bottom and a locking tab behind. 2.5" SSD mount holes are provided on the center platform. It also features a clever rubber-grommet decoupled HDD mounting system we will show you later.


A simple-to-use snap in and lock system is used to secure optical drives. Screws can be used on the other side for extra security.

ASSEMBLY NOTES

Our Phenom II X4 955 ATX case test system was installed without too much
difficulty. Hard drive installation was a snap, and cables were easily tucked
out of the way. Our standard modular PSU made things even easier.


Finished system with all the covers off. Neat, tidy wiring was relatively easy to achieve. This helps with airflow, cooling and noise.

The single most troublesome aspect of cable management was getting all the cables through the very small access hole in the top back corner of the motherboard tray. This little hole was the only path for too many cables. Making it twice the size would have been much better.


The focused oval shows the small hole through which two thick USB cables, the AUX12V cable and fan cables need to be routed.


The other side, where the cables were routed. More anchors or hooks for cable ties behind the motherboard tray would be useful. A little more space — even just a quarter inch, would also make putting that side cover back on a lot easier. The lower front fan was connected to the speed controller with an 8" extender — not included.

POSTSCRIPT 1, 2011-01-15: After this review was posted, a SPCR forum member pointed out that we had missed a second fan controller located in the top front corner, under the front bezel. This caused a rushed examination…. low & behold, there it was, awaiting our discovery. In our defense, tucked away as it is without any reference in the installation guide, it was easy to miss. This little PCB is identical to the other one in the back, with three fan headers, and it has the same effect on the fans. It is similarly inconvenient to access, as the front bezel has to be removed firs, like to top bezel for the back fans. But it does mean that at least the firing for the front fans don’t have to be routed all the way to the back.


Second fan controller in front, near the top, under the front bezel.


The HDD is installed in an unusual way. A specially shaped large head screw is used with a grommet that has a groove around it, much like the fan grommets. Once the grommets and screws are attached, they slide into a pair of rails, sort of like sled blades, in the hard drive cage. It is then soft-mounted; there is no hard contact between the drive and the chassis… although the amount of rubber between chassis and HDD is much smaller than with more conventional grommets.



The animated GIF above shows how all the hard drives in the cage are locked securely in place with a slide-lock and screw-tight mechanism. Again, it is ingenious and works well. (Refresh the browser window if the animation has stopped.)


The PSU was installed conventionally with four screws from the outside.

POSTSCRIPT 2, 2011-01-15: Initially, we tried to use the large L-shaped locking clamp the way show above… but this was the wrong way. The correct way is shown in the pictorial installation guide, as in the photo below.


With PSU bracket in place, this case can be shipped confidently with a system installed within. The clamp should stop the PSU screws from ripping the solft aluminum panel to which it is screwed, even subject to typical UPS drop-kick abuse. This is a common concern for system integrators who try to use alunimum cases.

TESTING

The same system used in many of our ATX case reviews was used again, for consistency.

System Configuration:

Measurement and Analysis Tools

  • CPUBurn
    processor stress software.
  • FurMark
    stability test to stress the integrated GPU.
  • GPU-Z to
    monitor GPU temperatures and fan speed.
  • SpeedFan
    to monitor system temperatures and fan speeds.
  • Seasonic
    Power Angel
    AC power meter, used to measure the power consumption
    of the system.

System temperatures and noise levels were recorded with SpeedFan and GPU-Z
at idle and on load using 4 instances of CPUBurn to stress the CPU, and FurMark
with the Xtreme Burn option to stress the GPU.

FANS

Lian Li has its brand on the fans in this case, but we know the company is not the manufacturer, which could be any one of the many DC fan makers in China. The basic geometry and design of the fans is decent. The four struts on both 120mm and 140mm fans have decent geometry and low profile for low noise potential. The 120x25mm is a moderately swept back 7-blade design, and the plastic does not exhibit excessive brittleness which can lead to vibration induced resonance. The 140x25mm top fan is a similar 9-blade design. Both use ball bearings. The accuracy of the specifications provided below is questionable. Lian Li does not provide full details, and much of the data was found on retailer sites. Since these fans are not effectively marketed or distributed, no serious effort was made to assess them individually; we focused on their overall cooling and acoustics performance in the context of this case, especially in unison with the built-in fan controller.


Back panel 120x25mm exhaust fan. The two in front are the same.
120 mm Stock Fan Specifications
Brand
Lian Li
Power Rating
3.24 W
Model Number
LI121225BL-4
Airflow Rating
56 CFM
Bearing Type
Ball
RPM Rating
1500 RPM
Corners
closed
Noise Rating
24.7 dBA
Frame Size
120 x 120 x 25 mm
Header Type
3-pin

Three of these 7-blade 120x25mm fans are provided in the Lian Li PC-B25S — two in front and one in back. Using the built-in fan controller settings, we listened to them and measured RPM as well as SPL while they were mounted on the case as shipped. There were no significant differences among them. The measured data is provided on the table below.

Subjectively, the 120mm fan was objectionably noisy at the maximum speed. Even at medium, it had a humming quality that was easily heard, especially if more than one of the fans was running. Only at the low setting could be judged as being smooth and quiet enough.


Top panel 140x25mm exhaust fan, with 3-position switch off one side.
140 mm Fan Specifications
Label
Lian Li
Power Rating
2.88W (Max)
Model Number
LI121425BE-4-A or CF-1410B
Airflow Rating
73 CFM
Bearing Type
Ball
RPM Rating
1000 RPM
Corners
Closed
Noise Rating
26.95 dBA
Frame Size
140 x 140 x 25 mm
Header Type
3-pin

The 140x25mm top fan has 11 blades instead of the 7 in the 120mm fans. Despite the 2 dBA higher noise spec, it sounds quieter and smoother than the 120mm fans at every speed setting. At full speed, it is not quiet, but it is smooth enough not to be too obtrusive. At medium, it is not too bad, and at low, it is quiet and smooth enough for most quiet-obsessed users.

Lian Li PC-B25S Stock Fan Measurements
Fan
Low
Med
High
RPM
SPL
RPM
SPL
RPM
SPL
140mm
640
15
750
19
970
26
120mm
830
16
1000
20
1280
28
Fans measured w/o grill or filter, in dBA, from 1m distance at 45° angle.

In summary, neither of the stock fans compare well with the established quiet leaders (Nexus and Scythe 120mm fans, particularly) but they are quiet enough at the low setting. With the case all closed up, and with the baffle over the top fan, they are much quieter in actual use than the above measurements suggest.

BASELINE NOISE

Noise measurements were made of the case with the rear, front and top fans
at low, medium, and high settings of the fan controller. Only one of the two front fans was connected, as the second one seems superfluous for cooling the test system… and because the fan controller has only three headers. The side mounted HDD drive cage impedes airflow enough that the front fans’ cooling effectiveness applies only to the drives; little of the flow from the front fans can be felt at the front edge of the motherboard, even when the fans are run at high speed. All the grills over the fans were removed; only the front fan filter was left on — this resulted in a 1-2 dBA drop in noise compared to all filters and grills on. The top baffle as well as the front bezel were left on.

The air cavity resonances inside
a case amplify fan noise, as do any vibrations transferred from the fans into
the case, so these measurements can be regarded as the baseline or minimum SPL levels for
the case and stock fans.

BASELINE NOISE
Speed
SPL@1m
Rear
(120 mm)
Top
(140 mm)
Front
(120 mm)
LOW
off
15 dBA
off
LOW
off
14 dBA
off
LOW
16 dBA
LOW
off
17 dBA
off
LOW
17 dBA
LOW
18 dBA
MID
off
20 dBA
HIGH
off
26 dBA
MID
22 dBA
HIGH
28 dBA
Measuring mic 1m at 45° angle left/front, roughly 1′ above top of case. Note: Adding the second front fan (using a splitter with the other front fan) increased SPL by 2 dBA on average. Subjewctively, it seems louder than that.

It is easy to see that all fans on LOW is a sweet spot for noise and airflow. Adding a front fan to the back and top fans on LOW makes no change to measured (or heard) noise, so it pays to keep it on. With three fans on MID, the noise level jumps 4 dBA; keeping the front fan off helps quite a bit, and at that speed, the back and top fans are pulling enough air through the front panel that the HDDs would get decent cooling anyway. The HIGH position is unacceptable to most silent PC enthusiasts, although many gamers would probably find it acceptable.


Optimum baseline noise with 3 fans on low measured 18 dBA@1m.

TEST RESULTS – CONFIG 1 (IGP)

Our test system running integrated graphics ran quiet and cool, measuring 21 dBA@1m at full load or idle. There was no point increasing any of the fan speeds as the cooling was more than adequate. At a meter distance, any cyclical or tonal idiosyncracies of fan noise were low enough in level to be effectively inaudible. There was a muted but still distinct hum which can be attributed to both the fans and the vibration from the hard drive. The vibration of the hard drive can be felt when any part of the chassis is touched. The 3 dBA increase from the sweetspot baseline low of 18 dBA is due to the addition of the CPU cooler fan and the vibration from the hard drive.

System Measurements (IGP)
System State
Idle
CPU + GPU Load
Fans
Back, Top and 1 Front on LOW
SPL@1m
21 dBA
CPU Temp
30°C
49°C
SB Temp
34°C
38°C
HD Temp
30°C
31°C
System Power
49W
189W
CPU fan set to 100% speed.
Ambient temperature: 22°C.

The screenshot of the frequency spectrum shows a sharp peak around 1200 Hz, but this is not really audible. The 2nd harmonic peak around 240Hz and the next harmonic at ~500Hz are much more audible; these are most likely caused by the vibration of the hard drive, whose fundamental noise peak can be seen at 120 Hz (corresponding to 7200 RPM). What we heard and measured confirms our earlier hunch that the rubber grommets for the HDDs are too thin to be very effective.


The IGP configuration measured 18 dBA@1m at full load.

COMPARISONS

IGP Configuration Comparison (Load)
Case
Lian Li PC-B25S
Fractal Design Define R2
Antec P183*
Antec Sonata Elite*
Active Fans
front, top, rear @ low
front & rear @12V
rear @low
rear @low
SPL@1m
21 dBA
19~20 dBA
19~20 dBA
20 dBA
CPU
48°C
51°C
50°C
55°C
SB
38°C
38°C
38°C
37°C
HDD
30°C
34°C
37°C
30°C
*CPU fan set to 9V rather than 12V.
Ambient temperature: 22°C (results adjusted accordingly)

Compared to the Fractal Design Define R2, Antec P183 and Sonata
Elite
, some established quiet cases, the Lian Li PC-B25S is a trifle louder but a touch cooler as well. It provided the best CPU and HDD temperatures, while being on par with the SouthBridge chip temperature.
It should be noted that the two Antec cases were tested with the CPU fan at
9V rather than 12V, which in our experience typically results in a 3~4°C
increase in CPU temperature and about half a dBA less noise at the 20 dBA level.
Also, both Antec cases were tested with a single fan in the rear exhaust position,
a 120 mm Antec TriCool fan. The fans in the Fractal are quieter than the Antec or Lian Li cases.

TEST RESULTS – CONFIG 2 w/ HD 4870

The second test system configuration adds a Radeon HD 4870 video card. This is a card we have used in ATX case reviews in the past. With gaming oriented cases, there has been a third configuration with dual 4870s in CrossFire, but as this case is not really oriented for gamers, we will stop with the single card. The AC power draw of this configuration at load is not low, reaching 330~335W in previous tests. The HD 4870, with its stock cooler, tends to ramp up its fan fairly quickly under load, making it the noisiest component at load in most systems. The challenge to provide enough airflow to the video card so that its fan stays at slower speed — without the case fans making more noise than the video card would. IWith previous cases, the best we’ve heard is around 25 dBA@1m at full load.


Test system with HD 4870 graphics card.
System Measurements (HD 4870)
System State
Idle
CPU + GPU Load
Fans
Back, Top and 1 Front
All fans* Med
Low
Med
SPL@1m
21 dBA
29 dBA
29 dBA
29 dBA
CPU
30°C
52°C
49°C
48°C
SB
34°C
52°C
50°C
48°C
HDD
30°C
31°C
28°C
28°C
GPU
79°C
88°C
86°C
86°C
GPU Fan
1100 RPM
2060 RPM
1900 RPM
1900 RPM
CPU fan set to 100% speed. Ambient temperature: 23°C. *The two front fans were paired with a Y-splitter and connected to the built-in fan controller. AC system power under load = 330~333W

Adding the HD 4870 graphics card had no appreciable temperature or noise impact on our test system when idle. Of course, AC power did jump. On load,
it made a substantial difference all around.

As this graphics card fan is often biggest source of noise in our test system when under load, and the GPU fan responds to air temperature changes, increasing case fan speeds can lower the overall noise. Not in this case. Whether with three fans on low or four fans on medium, the overall noise level stayed consistently at 29 dBA@1m. Component temperatures dropped a bit as fans were sped up or their total number increased, but the balance of noise from the various fan sources somehow remained constant at 29 dBA in this case.


The system measured 29 dBA@1m at full load with all fans at medium. The same basic result was also obtained with three fans on low, due to the increased speed of the VGA cooler fan.

The overall cooling was quite good, but as the comparison table below shows, it was at the cost of more noise than other mid-tower cases we’ve reviewed with the same system.

COMPARISONS

HD 4870 Configuration Comparison (Load)
Case
Lian Li PC-B25S
Antec 1200*
Fractal Design Define R2
Antec 902
Active Fans
4 fans
low/med
top, rears @low
rear, front & side @12V
rear, front @low
SPL@1m
29 dBA
25~26 dBA
26~27 dBA
27~28 dBA
CPU
47°C
46°C
48°C
49°C
SB
47°C
49°C
45°C
50°C
HDD
27°C
31°C
34°C
31°C
GPU
85°C
85°C
84°C
81°C
GPU Fan
1900 RPM
1760 RPM
1710 RPM
1860 RPM
CPU fan set to 100% speed
All temperature results adjusted to 22°C ambient.
*Antec 1200 tested with Antec CP-850.

Examining the above table carefully gives a pretty good picture of what is happening. In the Lian Li, the hard drive runs at a lower temperature than in any other case, because there is more airflow from the two front fans, running 830/1000 RPM. Those are the main sources of outside air in the case, however, and the side-mount HDD cage blocks much of that airflow (as with so many other sidemount HDD cages) so that less cooler outside air reaches the video card than in the other cases. As a result, the video card fan runs faster to keep the GPU at the same temperature as in the other cases. Once simple way to reduce the noise in the Lian Li (as in the other cases) is to set the HD 4870 fan cooling (easy to do with the latest versions of the Catalyst Control Center) for less aggressive cooling, allowing the card to run a bit hotter at the benefit of lower noise.

In any case, what is clear is that without a side vent (with or without fan) for the GPU, and the airflow-impedance of the side-mount HDD cage, the air in flow to the Lian Li PC-B25S is not quite up to par with the other mid-tower cases it is compared to here. The 29 dBA@1m measured here is not the quietest that the PC-B25S can run with a system of this thermal load. A change to a better aftermarket VGA cooler with quieter fans and more effective cooling could easily bring the noise level down closer to its baseline (close to 20 dBA@1m). However, the same can be said its competition.

FINAL THOUGHTS

The Lian Li PC-B25S is one of the more complex and perplexing cases we have encountered in some time. As we stated at the start of the review, some of its low-noise, performance and convenience oriented features are ingenious and well executed, some are smart but don’t work quite as intended, and still others don’t even make any sense or appear to be absurd errors. There are so many of these features that it is worthwhile to itemize them explicitly.

Special Features in Lian Li PC-B25S
Feature
Result
Unique rubber fan grommet mounts – Easy mounting/removal while providing vibration damping
OK but not great vibration isolation; back panel fan mount requires normal screw removal.
Unique rubber grommets and sled mount for side mounted hard drives – Easy mounting/removal while providing vibration damping
Poor vibration damping due to small amount of rubber between HDD and sled; reduced airflow due to impedance of side mounted HDD. Normal mounting allows air from front fans to flow more easily around the drives. This hurts cooling of higher power components, especially video card
Two Built in Fan Controller with 3-speeds – for convenient fan control and reduced noise
. The controllers are nice but the fans are not quiet / effective enough to make great use of the controller. Switch locations are inconvenient.
Four fans included with case
Generous, but fans are not quiet enough to be that useful for a silent PC enthusiast, even with the fan controllers.
Top airflow fan baffle/exhaust vent, lined to reduce noise
Seems to work OK, and looks pretty good, but noise reduction is minimal.
PSU bottom mounted on raised sleds to ensure cool intake airflow and minimze fan ramping
Works very well.
Lots of holes around motherboard tray for good cable management
Generally work well, but some holes are too small and more cable tie anchors are needed.
Handy clamp to keep PSU really secure, esp. useful in transit
Works well, ensure good security for shipping the case with a system installed.
Exhaust Fan Baffle/Deflector to reduce noise
Not tried because we know from past experience with similar devices that the effect is reduced airflow and decreased cooling with little or no effect on noise.
Front intake fan baffle to reduce noise
Unnecessary added cost, impedes airflow, which can result in poorer cooling and higher noise. But easy to remove. Front bezel already ensures indirect noise path to users.
Beautifully machined 2-piece aluminum disc feet to keep bottom intake vents above even thick carpeting
Works beautifully.
Thick aluminum panels, high quality construction Mostly very nice, impressive. Still evidence of increased hum due to lower density compared to good steel cases.
Foam lined side panels Good idea but… too thin and light. Noise reduction is minmal; so is vibration reduction.
Photo-illustrated installation guide Not terrible but not great. Makes no mention of fan controllers.
Dust filters, easily removable on fans to keep out dust Mostly work well, some mounted on wrong side of fan.
Tool-less PCI locking mechanism for quick, convenient and secure access to add-on cards
Works beautifully.

This may not be a complete list, but what we have so far is 7 thumbs up, 6 thumbs down, and 3 neutral/mixed. A positive balance overall. However, the elegant sexiness of the aluminum package has to be considered. Yes, this a personal thing, but there it is. The PC-B25S may not have the panache of a Porsche or even an iPad, but it is a pretty polished looking heap of anodized brushed aluminum. And the look, feel and appeal of a case lasts long after the excitement of all the latest hot component you install in it: The case, along with your monitor, keyboard, and mouse, are the visible hands-on, interactive points between you and your computer.

We are still not certain which way to lean. Straight out of the box and tested under our standardized conditions, the Lian Li PC-B25S provides good cooling and noise with a modest power system, but only mediocre acoustics with a higher power system. The biggest issue, in many ways, is the quality of the fans, which are not terrible by any means, but just not quite good enough. Replace all the fans with lower noise equivalents and many of the noise-related issues would fade, because the airflow-to-noise ratio would be improved. The cheapest good replacements are probably Scythe Slipstreams, and they could help the overall noise quite a bit. However, is it reasonable to spend another $25~40 on fans for a case that typically sells for over $200? It probably depends. It is if you can afford it and this is the case you want.

Improved fans do not cure the HDD vibration issue, but then again, there are hard drives with less vibration than the model we’ve been using for our case reviews. We use it specifically so that we can clearly assess differences in the ability of cases to damp HDD vibration. Choosing a quieter, lower vibration drive should help considerably. There’s always the smaller SSD + large quiet 5400~5900 RPM data drive combination that is still the best value/performance option these days. As for hot, noisy video cards, there are many aftermarket cooling solutions that can transform them, albeit, not without some cost (typically $50 or higher). (And for the inveterate silent PC modder, discarding the entire HDD cage for a DIY floating suspension rig for the drives would minimize airflow impedance from the front fans to the VGA card, while eliminating HDD vibration noise.)

In the end, buying or not buying a Lian Li PC-B25S case is a very personal decision. Viewed in a purely objective way, it is not the best purchase for value, noise or cooling. There are better balanced cases for less money. But human beings are rarely purely objective.

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