A find by some UK SPCR forum enthusiasts, the Euler is a surprising entry to the fanless thin mini-ITX case arena by a brand not closely associated with either silent computing or cases. Our exclusive review of this small, passively-cooled case from Akasa.
| Euler Thin ITX Fanless Case |
| £61.95 w/o VAT (w/120W power|
Thin mini-ITX is an Intel variant of the mini-ITX form factor, a variant that
first appeared in the Mini-ITX Addendum Version 2.0 to the MicroATX Motherboard
Spec v1.2 in Oct 2010. The first Thin-ITX (as its is often called) was Intel’s
("Johnstown") Atom-embedded board, which allowed the creation of very
low profile cases barely larger than the mini-ITX board itself, with the CPU
cooled passively. The more recent Intel
DN2800MT "Marshalltown" board with the Cedarview Atom processor
prompted Logic Supply to create a case designed specifically for it; regular
readers will likely recall my review of the Logic
Supply LGX AG150 system. The primary difference between thin and standard
mini-ITX boards is height: The standard mini-ITX boards typically have components
up to 44mm tall, while the thin ones are just 25mm, or an inch tall.
Thus far, Thin-ITX boards and fanless cases for them have been mostly Atom-based.
The recently introduced Intel
DQ77KB is one of the few retail Thin-ITX boards to feature a regular
socket which allows different CPUs to be installed. It’s a board that supports
the latest socket 1155 Ivy/Sandy Bridge processors.
In the OEM, industrial and commercial markets, there appear to be a few more
Thin-ITX boards. Intel envisions a mini-computer world dominated by the Thin-ITX
form factor, which is their specification. The web page, Thin
Mini-ITX-based Computing is Intel’s portal to its extensive vision for
the platform. Several Intel documents spell out the minutae of the specification
Thin Mini-ITX Based All-In-One PC Compliance Requirements, Aug 2012, rev
1.1, a PDF found cached on the web).
Based on boards shown in their Thin Mini-ITX Component Catalog (Q3, 2012),
socket 1155 and the precise position of the CPU socket on the Intel DQ77KB is
part and parcel of the current Thin Mini-ITX form factor: Photos of partner
offerings of boards by Gigabyte, ECS, and Wibtek all show the same layout. It
is not clear whether this means earlier Atom-based Thin ITX boards are no longer
complaint with the current spec. I did not examine the board layout of the Atom-based
DN2800MT in Logic Supply’s AG150 system that carefully, but I believe that board
also has the same layout.
In any case, all of this Thin-ITX development is aimed mostly at system integrators
to build All-in-ones and PCs for home entertainment, surveillance, digital signage,
point of sale and industrial applications. The enthusiast builder is not high
in Intel’s ecology of Thin ITX. But there are always exceptions.
recent buzz in the SPCR forums identified an unlikely source for a fanless
case for the DQ77KB and one other Intel board, the older DH61AG,
which has the same layout. The source? Akasa, known mainly as a cooling
accessories and component brand, with little presence in North America.
As expected of a fanlessly cooled case, the oddly named Akasa Euler
is a 7 liter case featuring a ribbed, heatsink-like top and side panels, and it
is low profile, though not quite as slim as Logic Supply’s offering for the
Atom-based boards. This is not surprising, as there will be more heat with a
non-Atom CPU, even with Intel’s applauded advances in lowering the thermal envelope
of its latest socket 1155 processors.
The interest in the Euler and these Thin-ITX boards has probably been spiked
by the market appearance of the Intel
NUC super-tiny computer, which we reviewed last month. Even though the
NUC is a very competent modern computer with a mobile Ivy Bridge processor at
its core, you pay a premium for its size and its fan does make some noise when
pushed really hard. The improved price/performance/value equation, and additional
features in the mini-ITX form factor boards with the extra power of a desktop
processor in a bigger but still small — and fanless! — package is
obviously compelling to some DIY enthusiasts.
AKASA UK, INTEL USA
It took some time and effort, but with some help from forum member Delta_42,
I managed to contact Alex at Akasa
UK who eventually rewarded my persistence with a sample of the Euler
case. Thank you Alex and Delta_42! In preparation for this case review, I also
contacted Daniel at Intel, who said initially that the DZ77KB board was not
being sampled (to reviewers), but then came up with what must have been a non-retail,
wholesale or system integrator sample — the board came complete with parts
but without a retail box. Then there was an Intel Pentium G2120 55W Sandy Bridge
sample slipped to me at IDF San Francisco in September, a CPU which hasn’t been
formally examined at SPCR yet. Thank you Dan! The 55W G2120 is somewhat higher
than the 35W TDP CPU that Alex recommended for the Euler case, but given how
cool most Sandy/Ivy Bridge processors run, I doubted it would pull much past
40W anyway. More on that later.
The Akasa Euler came in a small modest box, packed well enough, with a
rather large AC/DC 19V, 6.32A (120W) power adapter.
One problem was getting the screws, brackets, other hardware accessories and
installation sheet in a plastic ziplock bag out of the case, which was sealed
up tight. The four side-mounted screws were well hidden, or perhaps I was being
obtuse, but I didn’t find out about them until after I yanked the plastic bag
through the tight rear I/O panel opening and read through the installation sheet.
It was a tight squeeze, but no harm was done.
Here’s a photo that shows better the height of the ribs or fins… and
the position of the two screws on each side that hold the bottom panel
The specifications are minimal, too.
Akasa Euler Specifications
|Material||Aluminium with anodized black|
|Motherboards types||Thin mini-ITX with DC onboard|
|Dimensions||228 x 187 x 61.5mm (WxDxH)|
|Internal bays||1 (for 2.5” HDD)|
AKSA EULER DETAILS
Accessories include the aformentioned 120W AC/DC adapter, which is amusingly
branded "Great Wall." Its efficiency is not indicated. There are two
short SATA cables, a collection of screws, brackets for mounting a 2.5"
drive, a very short SATA power connector (to run from the Intel Thin-ITX boards)
and a lock for VESA mounting. The bottom of the case has four slot holes which
are intnded to be used with bolts threaded into the back of your monitor. The
case then hangs off the four screws securely, especially when the VESA lock
is used. The downloadable
PDF manual shows the steps clearly enough. That manual is mostly pictorial,
by the way, and good enough for the simple steps required to assemble a system
in the Euler.
The anodized brushed aluminum finish is nothing special, and it tends to pick
up and show dirt and finger oils quite easily. Good thing it is small enough
to be tucked away where it’s not too visible. Because of the lack of front panel
inputs, you won’t have much reason to access it physically especially if you
use sleep/hibernate mode like a good eco-citizen should. It’s a bit big, but
mounting it on any 20" or larger monitor will hide it nicely, and it’s
light enough not to be a concern for any monitor with a half decent stand.
About the lack of front panel ports and other facts about the Euler’s origins,
Alex of Akasa UK had the following to say in an email that came in just as this
article was being polished up for publication:
"Both the Akasa THIN Mini ITX Chassis, active and passive, were designed
and catered for Education and Digital Signage clients who did not require
these ports and in some cases did not even want a front power button. In fact,
we had not marketed the product at all and simply released the information
on the website, but received numerous inquiries, and production levels have
yet to meet the current demand.
"Based on Mike’s (from Viridian) recommendation, we contacted you, and
you are the first to review the chassis.
"We are planning more retail products as the THIN mini ITX boards become
more readily available, where front USB ports and probably SD Slots will be
prominent, although having said, that the boards currently only have USB 2.0
"Regarding availability, we should be looking at February before they
become easily and readily available in the US thorough our 3 resellers. As
you mentioned GBP 61.95 EX VAT would be the expected equivalent in the US;
thus USD 99.95 + Tax."
These comments help explain the Euler’s unadorned exterior and lack of external
ports. We’ll have to keep a sharp eye out for more Akasa introductions into
this market niche.
With the bottom panel removed, you can think of the Euler as a 5-sided heatsink.
The top panel does most of the work, of course, but since all of the other panels
(inlcuding the bottom once it is back on) are solidly connected to the top,
heat conducts everywhere, so the entire case becomes a convection cooler.
Those looking for some kind of sophisticated heatpipe or vapor chamber cooling
solution will be disappointed that a simple block of aluminum conducts CPU heat
to the Euler case. This is the same cooling approach in Logic Supply’s AG150
system. The difference is that the LS was designed for the heat of only one
embedded CPU; there is no variation in the CPU TDP of the DN2800MT board. With
boards the Euler was made for, users can choose from a wide variety of socket
1155 CPUs, including many that far exceed the 35W TDP said to be the approved
TDP limit of the case. The fact that this TDP limit is not actually specified
anywhere in the Euler’s description is a bit… convenient, perhaps? At least
for Akasa, if any ambitious user with a 95W processor complains of overheating.
Not that a 95W processor is likely to be used with either of the Intel Thin-ITX
boards; among the 40
compatible processors Intel lists for the DQ77KB board, none have higher
than 65W TDP. Ditto
for the DH61AG.
If the CPU candidates are limited to 35W TDP, the list becomes quite short,
perhaps 8 in total, and many are hard to find in the wild. Currently, only Intel
i5-2000 and i3-2000 series desktop dual cores with the T suffix (such as i3-2100T),
and Pentium G600 series dual cores, again with the T suffix, are 35W. At time
of writing only one 35W socket 1155 processor is available at Newegg: An i3-2120T
2.6GHz Dual-Core with Intel HD Graphics 2000. Not exactly a pulse raiser for
$125. We’ll have to see how the Euler handles the 55W Pentium G2120 on hand,
a dual core that is both faster (3.1GHz) and cheaper ($95 at Newegg) than the
The area on the underside of the top panel next to where the heat block
COMPONENTS FOR THE TEST SYSTEM
There are only two components the Euler is designed to house: One or the other
of the Intel Thin mini-ITX boards, and a 2.5" form factor drive. The latter
can obviously be a notebook drive, or more ideally, an SSD. Both the Intel
DQ77KB and the DH61AG,
are fitted with mini-PCIe slots that can support mSATA SSDs, similar to the
Intel NUC, where mSATA is the only storage option. The 180GB Intel 525 mSATA
SSD which came with our sample of the NUC was pulled and used for this review.
HyperX 3K 120GB 2.5" SSD was also tried. In practice, both a 2.5"
SSD and an mSATA SSD could be used. Or for someone wanting more value storage,
an mSATA SSD for the operating system and programs, and a 1TB or bigger 2.5"
HDD. The latter would spoil the no-moving parts status of the system, though.
Components for System in Akasa Euler case
The Intel DQ77KB board is packed with goodies, including two mini PCIe
slots (one half, one full/half), dual gigabit ethernet ports on separate
controllers, 4 USB 3.0 ports, 4 SATA ports, HDMI and DisplayPort video
outputs, etc. Power comes from any 19V DC source with the right connector
(typical notebook power adapter) and power for peripherals comes via a
SATA power jack on the board (from which sprout those cables in the pic
above). All caps look solid state. For full details, please check out
the link to the Intel
HyperX 3K 120GB 2.5" alternative to the mSATA SSD.
It starts with pulling two screws from each side of the Euler case. This releases
the bottom panel. The 2.5" drive and the motherboard both screw into the
underside of the top panel, which is the primary heatsink for both CPU and drive,
though even a HDD only dissipates 1W on average, and perhaps 2.5W max. An SSD
runs a bit cooler.
Two aluminum bars are affixed to the SSD, then the protruding tabs are used
to screw down the SSD to the case. Cables from the drive and case power switch/LEDs
get connected to the board. Of course, the CPU is in place by now. A generous
dollop of TIM (about the size of a BB) is placed atop the aluminum heat block.
Then the board is positioned so the four standoffs on the CPU heat block fit
into the heatsink mounting holes in the board. This automatically lines up the
four board mounting holes around the perimeter.
I chose to affix the nuts for the CPU heat block first, to ensure best tightness
between CPU and heat block. The supplied round nuts are tiny and require a flat
blade screwdriver to tighten. This, to me, is a bad decision on a part that
probably costs less than a cent. The nuts have tiny slots, and the screwdriver
blade slipped once — but once is all it would take to destroy one or more
of the trace-side components on the motherboard and make it useless. It didn’t
happen to me, but a nicely designed low profile thumbscrew with a center Phillips
head would have been so much better. The four corner screws to secure the motherboard
went in without issue.
A flat blade screwdriver is needed to secure the nuts around the CPU.
After the motherboard was installed, I removed it immediately to examine
the imprint of the thermal goop. As you can see in the above pic, the
contact was decent, but perhaps it could have used a tiny bit more goop.
Windows 7 Ultimate 64-bit was installed from a USB key without issue, and we
were up and running 20 minutes after the case was closed up.
The focus here is primarily on the cooling ability of the Euler case, and
secondarily, on the power brick which came with the case. SPCR’s usual suite
of thermal and power tools were called into play. The system’s thermal and power
characteristics are recorded in idle, CPU stress and CPU+GPU stress conditions.
The extended stress conditions, using Prime95 and Furmark, are totally artificial
and over the top. Virtually no useful application actually can make components
run as hot, but it gives us a good reference by which to compare the performance
of cooling solutions.
Measurement and Analysis Tools
Before getting to the performance of the case, my impressions of this system,
using either the Intel 525 mSATA SSD or the Kingston HyperX 3K SSD: It is quick,
much quicker than you might expect of a "lowly" dual-core Pentium.
It is still a 2nd gen Core Sandy Bridge chip and retains much of the performance
of the pricier i3/i5 chips. For those who are curious, it is quicker than the
Intel NUC. There is nothing I cannot do with this system that I can do with
a Z77-chip i5-2500K ATX desktop. Except serious 3D gaming, of course, as this
system is limited to the Intel HD graphics… which does a perfectly good job
with everything else.
The system was kept in each state for a minimum of 30 minutes. It is when the
temperatures don’t change for 5 minutes that stability is deemed to be reached.
For the stress loads, stability was reached after nearly an hour. The entire
case heats up, so it takes quite a while to reach stability. For Prime95+Furmark,
the AC power began at around 50W, and it increased to 55W over time due to decreased
efficiency as power components (especially the VRM) became hotter. This is normal.
Akasa Euler System Measurements
Prime95 + Furmark
Ambient temperature: 22°C.
CPU – highest core temperature of processor
PCH – temperature of Platform Controller Hub (motherboard chip)
VRM – temperature of voltage regulation module
DIMM – temperature of RAM memory
SSD – temperature of Solid State Drive
Case – highest temperature on external casing
The temperature readings come mostly from AIDA64 Extreme Edition, which matches
SpeedFan readings almost exactly. What’s clear is that in any normal usage,
the Euler keeps this CPU and motherboard perfectly cool enough for stable, long
term use. Yes, at full tilt, with both CPU and graphics cores pumped to the
max, everything gets pretty hot, yet the CPU never throttled, and not once did
any kind of overheating misbehavior occur during testing. It’s a short, positive
outcome after the lengthy leadup: The Euler case works as intended, cooling
the CPU and motherboard passively without making any noise. That’s right, even
with my ear almost directly atop the case or the power brick, there was no noise
to be heard. OK, it’s possible there was some hint from the power brick, but
it’s irrelevant because the level is so low as to be immeasurable and inaudible.
The 62°C measured at the hottest spot of the external casing is too hot
to touch. In normal use, the case got warm but never too hot to touch. Changing
the 2.5" SSD for the mSATA SSD had virtually no impact whatsoever on temperatures.
Power might have been up by 1W with the SSD in some instances, but it’s too
small a difference to consider significant.
The 55W TDP of the Pentium G2120 turned out to be a false alarm. Since the
AC power draw never exceeds 55W, there’s no way it could possibly pull 55W by
itself, at least not with our torture test apps. The latest version of AIDA64
Extreme Edition has an extremely interesting and useful addition in
its sensor monitoring, which I believe probably works only with newer motherboards
(and components): It tells us the power pulled by the CPU. Its accuracy is open
to question, but the data is worth looking at. See the screen capture below.
AIDA64 Extreme Edition Sensor page for Intel DQ77KB w/ Pentium G2120
in Akasa Euler case at full system load.
The Power Values heading indicates the power drawn by the CPU. I believe CPU
Package indicates the total power drawn by the CPU. Does 23W sound too low for
a minimalist system that draws 55W AC total? Perhaps. It has to depend on motherboard
sensors, and they can certainly vary even from sample to board sample. On the
other hand, AIDA64 indicates 61W CPU Package for a Core i5-2500K in a Z77 board
while running just Prime95, which seems pretty close to what I’d expect.
The Great Wall 120W power adapter was swapped out for comparison with a recent
Dell 19VDC 80W power adapter that has high "V" efficiency rating.
The difference in AC power demand in the various states between these power
adaptes was less than a watt, so I can safely say the included power brick is
probably >85% efficient, perhaps 87% at the full 55W power draw, about as
good as power bricks get these days. The total system idle power of 16.5W is
very modest, not as low as an Intel NUC, but then it’s also a more capable system.
Akasa has come up with a practical, no-moving-parts mini case in the Euler.
It was obviously intended for applications where silence, dust-resistance, zero
maintenance or no airflow to disturb the environment are important, and it fulfills
this role well with the recommended components, specifically, a lower TDP CPU
mated with one of the Intel Thin-ITX boards. The cooling capability of the Euler
is good enough for a Pentium G2120’s 55W TDP, so anything in that range or lower
would be perfectly good. Unless you’re going to be pushing the system consistently
hard in high ambient operating temperatures, even a 65W TDP processor might
not pose much risk.
The combination of a cool Sandy or Ivy Bridge CPU, Intel DQ77KB mini-ITX board,
lots of fast RAM and an SSD is a persuasive argument for small, silent, low
power computing. Hung on the back of a good monitor with a wireless keyboard
and mouse with perhaps a USB 3.0 hub on your desk, you’d never know a Euler-based
system was even there. As a media PC with access to a home server, a Euler-based
HTPC system could sit idle just about anywhere near your big panel TV and never
make a sound except that which comes through the speakers when you’re playing
If Thin Mini-ITX succeeds in becoming widely accepted as a mini computing platform
as Intel obviously hopes, the Euler is surely only the first of at least a few
more fanless cooling case solutions to come. Akasa’s own comments suggest that
they are looking at the possibility of similar passively cooled, more consumer-friendly
Thin-ITX cases. For now, the Euler appears to be the only passive cooling case
dedicated for Thin-ITX and available to the retail buyer.
At the anticipated $99 selling price with an efficient 120W adapter, the Akasa
Euler represents good value. The total market price of the hardware assembled
for the test system is around $500, hardly any more than a mATX with similarly
spec’d components in a case that would have to be at least four times bigger. If you’re OK with the integrated graphics, this is a great small computer solution that still provides some degree of options for the DIY enthusiast, unlike most complete mini PCs, which offer much less choice and rarely zero noise. A recommendation is without question.
Our thanks to Akasa
UK for the Euler case sample.
* * *
Akasa Euler is Recommended by SPCR
* * *
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