Antec ISK 100 Mini-ITX Case

The Antec ISK 100 is a followup to the ISK 300, a smaller case without the 300’s steel exterior, optical drive bay, expansion slot, and 8 cm fan(s). The ISK 100’s most interesting features are its well-ventilated mesh cover and 10cm fan which should provide excellent cooling.

Antec ISK 100

March 20, 2011 by Lawrence Lee

Antec ISK 100
Mini-ITX Case

The mini-ITX form factor is undoubtedly growing in popularity, but there still
isn’t much choice in cases. The market is dominated by a myriad of low quality
generic/OEM cases with limited cooling capabilities. A number of Shuttle-style
breadbox shaped cases are good options for those who seek high performance and
cooling good enough for hot CPUs, but there are few cases that take full advantage
of the very small size of the mini-ITX. Antec is one of the few big name chassis
manufacturers with a line of compact mini-ITX cases, and more importantly they
actually make cooling a priority without overly expanding the dimensions.

The box.

The ISK 100 is a smaller follow up to the ISK
. The 300, with a "floor to ceiling" (or side-to-side if
the case is positioned vertically) dimension of nearly four inches, isn’t particularly
slim. That 4" dimension is necessary as it is equipped with an 80 mm fan
with the option for second. It is akin to a breadbox style case chopped to half
height. The ISK 100 is a more minimalist approach, sacrificing both the optical
drive bay and expansion card slot for a smaller chassis. The exterior is composed
of plastic rather than steel, and much of the side panel is mesh to provide
plenty of fresh air to the top of the motherboard. Rather than an 80 mm fan,
the ISK 100 is armed with a thin 100 mm exhaust fan positioned on the side meshed
panel. (Note: Since it comes with a stand to position it vertically,
enabling the smallest footprint atop your desk, we’ll be referring to the panels
paralled to the motherboard as the sides.)

Package contents: power cable, power adapter, screws, and insulation strips for hard drive mounting.

AC power brick.

The ISK 100 ships with an AC power brick rated for 90W, enough to power most
contemporary dual core desktop CPUs. At most, we would recommend a TDP of 65W
or lower for AMD processors and 73W or lower for Intel chips. Using integrated
hardware based on Atom, CULV,
ION, and/or Fusion components
would be no problem as they typically use less than 45W total including basic
system components. The case does not support any expansion cards so discrete
graphics are out of the question, not that there would be enough power to drive
anything more than an entry level model.

Features & Specifications: Antec ISK 100
(from the
product web page
2 x 2.5" internal drive bays
ABS plastic/0.8 mm SECC construction
Special extruded housing for fan
Includes standard case lock slot for integrated anti-theft protection
Stand included
No expansion slots
Cooling system
– Side 100 mm TwoCool™ fan with switch controls
Front ports
– 4 x USB 2.0
– HDA/AC’97-compatible audio in/out
Motherboard compatibility: Mini-ITX only
90-watt adapter plus PCB for stable and reliable power
Unit Dimension
– 248 mm (H) x 70 mm (W) x 212 mm (D)
– 9.8" (H) x 4.3"* (W) x 8.3" (D)
[*note: appears to be a typo, should be 2.8"]
Package Dimension
– 505 mm (H) x 296 mm (W) x 368 mm (D)
– 19.9" (H) x 11.7" (W) x 14.5" (D)
– Net : 2.6 lbs / 1.2 kg
– Gross : 4.8 lbs / 2.2 kg


The exterior dimensions of the ISK 100 are 24.8 x 7.0 x 21.2 cm or 9.8 x 2.8
x 8.3" (H x W x D, when oriented vertically) with a volume of 3.7 liters.
Its big brother, the ISK 300 is narrower and taller by about one inch, but is
4.6" deeper; the 7 liter volume makes it nearly twice as big as the 100.
The case weighs just 1.2 kg or 2.6 lb out of the box.

The plastic exterior is pleasant enough, but the protruding off-center
fan is a bit of an eyesore. It is positioned to be directly above the
processor/heatsink of most mini-ITX motherboards.

The side panels are secured with a pair of screws each. There is additional
ventilation at the sides.

The other side is not nearly as well ventilated with just a few slits
running down the edges.

Once the screws are removed, the two covers simply pull apart. They are loosely attached to the rest of the chassis using round tabs, like the ones found on the front bezels of numerous tower cases.

The 100 mm fan has 13 very thin blades. With curved struts and a support ring between the hub and exterior casing, it resembles Scythe’s 12 mm thick Slip Streams.

A small switch is located at one corner to control the fan’s speed.
There are only two settings. It is inconveniently located on the


The interior of the ISK 100 is very basic with a DC-to-DC power supply on one
end, and a simple hard drive tray beneath the motherboard. The worst thing about
assembly is the very tight spacing. It took us a few tries to figure how to
angle the motherboard into place, and afterwards we struggled to keep cabling
away from the edges of the case and the fan.

The interior.

The front panel cables were much too long. The power supply had the
cables with the following connectors: 20+4 pin ATX, 4-pin AUX12V, 2x SATA,
1x 4-pin molex. The last is completely unnecessary and just causes more

The ISK 100 supports a pair of 2.5" drives, installed underneath the motherboard.

We chose an LGA775 motherboard, the Zotac GeForce 9300-ITX, because
its CPU socket is directly under the ISK 100’s fan. LGA1156 boards like
the Intel DH57JG (pictured on left) position the processor near the other

The case allows a maximum CPU cooler height of only 40 mm, forcing
us to use an Intel stock cooler with the fan removed (35 mm tall).

As you can see, the fan was positioned almost perfectly above the
heatsink with the hub slightly askew from the copper core of the CPU cooler.


Our main issues with the ISK 100 concern fit and finish. The coveer panels
were a little ‘off’ as was the I/O shield, the stand, and the screws provided
for the hard drive. None of these items aligned just right once the motherboard
was put in place. Perhaps there’s just enough twisting to cause this misalignment.

The hard drive screws were too long, made it impossible to clamp the
drives securely. We had to scrounge up screws to mount the OCZ Vertex
30GB and WD Scorpio Blue 500GB drives.

Drives installed.

The corner of the cover near the AC power jack didn’t quite line up
with the rest of the housing, at least not until we screwed it down. We
ran into the same thing on the opposite corner.

Also, if the covers are screwed on tight, the sides compress, making
the holes for the stand too small to use. The stand has to be installed
before the screws. This discovery took a lot of effort.

The back panel was also misaligned, partially blocking off the RJ45 connector and a pair of USB ports.

Installed and running. Note the red LEDs on the interior were from our Crucial Ballistix Tracer DDR2 memory.


System Configuration:

Measurement and Analysis Tools

System temperatures and noise levels were recorded with SpeedFan and GPU-Z
at idle and on load using Prime95 (large FFTs setting) and FurMark, an OpenGL
benchmarking and stability testing utility.


As the ISK 100 uses an external fanless power supply, the only source of noise
from the case is its 100 mm 3-pin stock fan which unfortunately is attached
to the rather weak mesh panel, hanging off it with little structural support.
As a result, the overall acoustic profile was rough, with several points of
tonality. The bearings produced noticeable chatter, with a persistent rattle
that grew with fan speed. It also produced both a high frequency buzzing and
a low frequency hum.

Stock Fan Measurements
SPL @1m
SPL @0.6m
12V (high)
1880 RPM
30 dBA
34 dBA
1630 RPM
25~26 dBA
30 dBA
7.6V (low)
1450 RPM
22~23 dBA
26~27 dBA
1360 RPM
21 dBA
23 dBA
1200 RPM
18 dBA
19~20 dBA
1000 RPM
14~15 dBA
17 dBA
Measuring mic positioned 1m at diagonal angle left of top cover of case (vertical stand).

The noise level ranged from 30 dBA@1m at a full 12V, down to 14~15 dBA@1m at
5V. Setting the manual speed switch to ‘low’ put the speed at 1450 RPM, which
was equal to 7.6V with the switch on high. The fan became what we consider quiet
at about 6V with the switch on high.

Baseline noise with the stock fan at 6V.


Thermal Performance

Our first test is to determine what fan speed is required to keep our test system sufficiently cooled. The integrated GPU on our Zotac GeForce 9300-ITX motherboard becomes unstable at about 95°C so we would prefer to keep it under 85~90°C if possible.

System Measurements (CPU + GPU Load)
Fan Voltage
AC Power
Avg. Core
7.6V (low)
23 dBA
27 dBA
22 dBA
26 dBA
20 dBA
24 dBA
18 dBA
22 dBA
Ambient temperature: 19°C.
Ambient noise level: 11 dBA.

For our test system, the stock fan was more powerful than necessary, as we
did not have to run it anywhere near maximum speed to keep the system cool.
The sweet spot was 6V, which produced temperatures of 54°C and 70°C
respectively for the CPU and GPU, and a noise level of 20 dBA@1m. At 5V, the
GPU temperature rose precariously close to 90°C.

The biggest problem was the hard drive, which lacks ventilation. Jammed underneath
the motherboard tray, it heated up to almost 50°C. Incidentally, our WD
Scorpio Blue drive added about 1~2 dB to the noise level at 6V~7.6V. It generated
about 18 dBA@1m on its own.

System Measurements (Fan @ 6V)
AC Power
Avg. Core
H.264 Playback
CPU + GPU Load
Ambient temperature: 19°C.
Ambient noise level: 11 dBA.
System noise level: 20 dBA@1m, 24 dBA@0.6m.

With the fan at 6V, temperatures were quite comfortable when idle and during video playback.

System noise level with the stock fan at 6V.

The power supply (DC-DC converter board and AC-DC adapter) was not formally
tested, but it seemed to do a fine job. Efficiency was estimated to be at least
80%, possibly up to 85%.


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 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.


The Antec ISK 100 provides enough power (90W) and cooling for a typical mini-ITX
dual core desktop processor combination (or even a low power quad core). A low
noise level can be achieved but only with additional fan control, as the fan’s
low speed setting is a bit too high. Lower power configurations like those based
on Atom, ION, CULV, or Fusion should do very well as they require only minimal
amounts of cooling. On the down side, there is no option for an expansion card,
or an optical drive, and not much clearance for a CPU cooler, although our solution
of yanking the fan off a stock heatsink is easy enough for anyone to use.

The basic design is simple and effective, but the quality of execution is wanting.
Our overall impression is a case slapped together with not enough attention
to detail. The screws for the hard drives being too long and the apparently
misaligned back panel are simply unacceptable — these are basic, essential
requirements. The interior provides just enough room for the board and cables
with no extra breathing room at all, making it a pain in the ass to assemble.
The plastic covers don’t fit quite right with little gaps visible at the back,
and once screwed in the stand cannot be mounted.

The hard drives need more ventilation, and the mesh panel on the other side
needs to be stronger to be a stable base for the fan. Finally, given its central role in both cooling and noise (or quiet), the fan should have been more carefully selected. It certainly does not have to be capable of ~2,000 RPM; 1,500 RPM would be good enough for any CPU that is likely to be used in this case. A smoother sounding fan with a more suitable speed range would have made the ISK 100 a much better product. We think a centered 120 mm fan would make it more suitable with a wider variety of mini-ITX boards.

As it stands, the ISK 100 is an adequate but not exceptional product. If you
need a very small desktop case for a specific must-use mini-ITX board, it is
one of the few choices available. On the other hand, similarly small (or even
smaller) pre-packaged mini systems from Zotac, Asus, Acer and others enerally
offer better integration of the components, and they can be just as quiet.

Our thanks to Antec for the ISK 100 case sample.

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this article in the SPCR Forums.

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