Viako Mini Letter ML-45 LEAP E-350 Barebones Nettop

Table of Contents

The Viako Mini Letter ML-45 is a barebones nettop from Korea featuring an AMD E-350 APU, a Giada mini-ITX motherboard with 802.11n and Bluetooth, all wrapped up in a stylish and thin aluminum chassis with an LCD display and Media Center remote control.

July 8, 2011 by Lawrence Lee

Product Viako Mini Letter
ML-45 LEAP E-350
Barebones Nettop
Manufacturer Viako

Viako is a Korean company with a line of slick SFF/HTPC cases, barebones, full systems, and accessories that apparently have a fair-sized following in Asia. Their cases all have a small footprint but vary in size, mostly in thickness. Their more complete solutions are agnostic when it comes to hardware, utilizing Atom, ION, Fusion, and even Sandy Bridge chips. Our first sample from Viako is the Mini Letter ML-45, a thin mini-ITX barebones with an AMD E-350 APU and Giada motherboard.

The box.

The Mini Letter ML-45 ships in a whimsical box sent through time complete with blue and red “air mail” accents on the edges and even postage paid stamps. It makes us nostalgic for the good old days when people actually looked forward to mail and penmanship was legible.

Package contents: ML-45, AC-to-DC power adapter, remote control, batteries, WiFi antenna, driver disc, and manual.

The package contents on the otherhand are anything but a blast from the past. The ML-45 is a diminutive barebones PC with a sleek aluminum casing housing and the latest in nettop technology: AMD’s Fusion E-350 accelerated processing unit consisting of a dual core 1.6 GHz CPU and Radeon HD 6310 graphics. Though not exactly a stellar performer, the E-350 still runs circles around Intel’s Atom processors and the graphics chip is more than capable of decoding full high definition video. It has all the right hardware for a media PC including connectivity options like 802.11n and Bluetooth. The included remote, front panel display, and the application(s) running may be what makes or breaks the experience; Too often these are just thoughtless add-ons.

Viako Mini Letter ML-45 LEAP E-350: Specifications
(from the product
web page


The ML-45 measures just 22.0 x 21.5 x 4.4 cm (W x D x H) or 8.7 x 8.5 x 1.7 in, making the total volume about 2.1 liters. Its thickness is comparable to most nettops but its footprint is a bit on the large side. A vertical stand was omitted as it would have made the LCD difficult to read.

The chassis is a rounded square of aluminum just 1.7″ tall, precluding the use of an optical drive. The front panel is completely solid except for the display and remote sensor. Small slits on each side (both top and bottom) and a 40 mm fan provide ventilation.

HDMI, VGA, and S/PDIF are offered on the back panel but the big limitation is lack of USB ports as only four are provided. The rear is also home to the power switch which normally be a nuisance if not for the remote control’s ability to turn the PC on.

Thankfully the grotesque rubber feet are hidden by short columns of aluminum.

The power adapter is a 12V/5.0A model manufactured by Li Shin.

The remote has a few extra buttons that separates it from a typical Media Center remote. Direct line of sight with the receiver is required which makes it a bit of a pain to use at closer distances.

The other half.


Removing the four screws allows one to take off the top cover revealing a mini-ITX motherboard (manufactured by Giada) with a single DDR3 SODIMM slot, two mini PCI-E slots, one 2.5″ drive tray and a pair of SATA connectors.

Though wired rather messily, the interior is not particularly cramped, at least not for a board and system of this type.


The only expansion option is a second mini PCI-E slot (the first is populated by an Atheros 802.11n WiFi adapter) sitting underneath the 2.5″ drive tray which positions the drive upside down. There’s a slot style cooler over the CPU which directs air toward a similarly puny-sized exhaust fan on the right side.


With the limited options and most of the peripherals already plugged in, assembly only takes a minutes. All that’s required is a DDR3 SODIMM and a 2.5″ drive. We used a 2GB stick of Kingston ValueRAM DDR3-1333 and a Seagate Momentus XT 500GB hybrid notebook drive.

The ML-45 lacks a power LED but the display activates immediately when the turned on. It can be set to display a variety of different tidbits of information.

Here’s how it appears in the dark.


Test Configuration Components:

Device listing. Note: the unknown device is an Atheros Bluetooth adapter. The driver was installed during testing.


Measurement and Analysis Tools

  • CPU-Z
    to monitor CPU frequency and voltage.
  • CPUBurn
    processor stress software.
  • Prime95
    processor stress software.
  • ATITool
    artifact scanner to stress the integrated GPU.
  • FurMark
    stability test to stress the integrated GPU.
  • Cyberlink
    to play H264/VC1 video
  • Real Temp
    to monitor CPU temperatures.
  • Core Temp
    to monitor CPU temperatures.
  • SpeedFan
    to monitor system temperatures and fan speeds.
  • Seasonic
    Power Angel
    AC power meter, used to measure the power consumption
    of the system
  • Infrared Thermometer to measure external temperatures.

H.264/MKV Video Test Clip

MKV (Matroska) is a very popular online multimedia container
used for high definition content, usually using x264 (a free, open source
H.264 encoder) for video. The clips were taken from two longer videos —
the most demanding one minute portions were used. To play them we use Media
Player Classic Home Cinema which by default utilizes DXVA (DirectX Video
Acceleration) with supported GPUs. For graphics chips that do not support
hardware acceleration for either codec, the software decoder CoreAVC is
used to render using CPU power alone.

1080p | 24fps | ~14mbps

x264 1080p: Spaceship is a 1080p x264 clip encoded from
the Blu-ray version of an animated short film. It features a hapless
robot trying to repair a lamp on a spaceship.


Our test procedure is designed to determine the overall system power
consumption at various states (measured using a Seasonic Power Angel). To stress
CPUs we use either Prime95 (large FFTs setting) or CPUBurn depending on which
produces higher system power consumption. To stress the GPU, we use ATITool
or FurMark, which ever application is more power demanding. Temperatures and acoustics are also recorded.

All nonessential pre-installed software is removed prior to testing, and certain
services and features like Superfetch and System Restore are disabled to prevent
them from affecting our results. Aero glass is left enabled if supported. We
also make note if energy saving features like Cool’n’Quiet and SpeedStep do
not function properly.

Fan Control & Acoustics

The BIOS of the Giada motherboard used in the ML-45 offered a few different fan control options for both the CPU and System fan. Either fan could be set to full speed, manual (static), or automatic.

Automatic fan control options.

Automatic mode can be configured with the starting speed (a duty cycle value between 0 and 255), the slope of the curve (how fast the speed increases), and the temperatures at which the fan starts/stops. The default settings had the System fan at full speed and the CPU fan starting at a value of 140. After playing around with system for a few hours we found that it remained adequately cooled without any fan speed increases over the stock settings, so we made only one adjustment: changing the CPU fan mode to manual and leaving at its starting value.

SpeedFan with correlations entered.

Windows users have the option of using SpeedFan to control both fans. Changing the IT8721F chip’s PWM 2 mode value from “ON/OFF” to “Software controlled” in the Advanced menu allows full voltage control over the two fan headers using the Speed04 and Speed05 controls. Unfortunately SpeedFan lacked a CPU temperature sensor so for that other software such as Core Temp is required.

System Noise
CPU Fan Speed
System Fan Speed
SPL @0.6m
20~21 dBA
23 dBA
33 dBA
Ambient noise level: 10~11 dBA.

Without any fans turned on the system (or rather the hard drive, being the only component with moving parts turned on) measured 20~21 [email protected]. Our chosen fan control settings resulted in a measurement of 23 [email protected], which means it effectively doubled the noise level. The System fan was drowned out by the CPU fan despite running at 100% speed so we can understand why full on was its default setting. By comparison the CPU fan at full speed brought the noise level to an earsplitting 33 dBA@1m.

The ML-45 with a Seagate Momentus XT installed measured 22~23 [email protected] using our custom fan settings.

Using our custom settings the fan acoustics were excellent, surprisingly soft given the size of the fans in question; tiny 40 mm models tend to be particularly whiny and tonal but no such affects were noticeable at this level. While we didn’t have any complaints regarding the fans, the noise generated by the ML-45 was poor because it suffered from some horrific and random coil whine. In a quiet environment it was easy to pick out the high pitched squeaks and squeals coming from the voltage regulation circuitry of the CPU/motherboard. In the graph above it seemed to manifest at the >10 KHz where there’s a spike of about -5 dB. The coil whine would stop briefly from time to time, but only went away when turned off, put to sleep, or put on a heavy load.

Thermal Performance

System Measurements
System State
Power (AC)
Sleep (S3)
H.264 Playback
CPU Load
CPU + GPU Load
Ambient temperature: 21°C.
Ambient noise level: 10~11 dBA.
System noise level: 23 [email protected].
*External temperature measured using an IR thermometer pointed at the hottest portion of the chassis (near the 40 mm exhaust fan).
Note: disabling the VFD/remote software resulted in an average power consumption reduction of 2W.

Despite being jammed in a cramp enclosure with limited airflow, the CPU and HDD remained adequately cooled during testing even on heavy load. At full tilt with both the CPU and GPU stressed beyond normal limits, the CPU temperature stabilized at 76°C while the hard drive and external temperature did not exceed 35°C. There was no instability or other anomalies during testing either. If you’re not planning to push the system as far as we did, it’s likely you can reduce the fan speed and shave 1~2 dB off the overall noise level.

Nettop Comparison
Test State
(SU2300 + ION)
Viako ML-45
CPU Temp
System Power (AC)
CPU Temp
System Power (AC)
H.264 Playback
CPU Load
CPU + GPU Load
SPL @0.6m
24~25 dBA
23 dBA
Ambient temperature: 21°C.
Ambient noise level: 10~11 dBA.

The closest system we’ve reviewed to the ML-45 is the Zotac ZBOX HD-ND22 with a dual core Celeron processor and Nvidia ION graphics. The two machines were neck and neck thermally until they were put on load. With more energy efficient hardware, the ML-45 managed to keep the CPU temperature reasonable while the ZBOX approached 100°C on full load and generated 1~2 dB more noise. Keep in mind the Celeron is a significantly faster processor.

Boot & WiFi Performance

While a media PC is probably best placed in standby/sleep to be turned on in mere seconds, the ML-45 had an impressive cold boot time of 10.4 seconds (measured from pressing the power button to the “starting Windows” screen when the speed of the O/S drive takes over) which is 2~3 seconds faster than most mini-ITX boards we’ve encountered in the past. The ML-45 has the advantage of not supporting a whole lot of peripherals, so there aren’t that many things for the BIOS to check before booting up. The POST screen disappears quickly and doesn’t even display a prompt for entering the BIOS.

The performance of the Atheros 802.11n adapter was good as well, holding a five bar signal throughout testing without one disconnection from our D-Link wireless 802.11n router placed 25~30 feet away between a wall. A large file transfer (~1.4 GB) completed with an average speed of 75.2 mbps which is almost twice the speed required for streaming a high bitrate Blu-ray movie.

Remote & VFD

The remote and VFD are controlled by a program called M.Play MX which is apparently produced by Moneual. While it packs quite a bit of functionality it isn’t as expansive as their iMon application which can be used to mimic a mouse, bring up an on-screen keyboard and even execute macro commands. It seems to slightly more user friendly, though this might just be an illusion created by its relative simplicity.

The “Quick Guide” button opens up an app launcher for up to 10 program shortcuts.


Custom key bindings can be created for countless number of programs like PowerDVD, KMPlayer, QuickTime, WinAmp, WinDVD, WMP, and XBMC.


The LCD can be configured to display CPU, RAM, temperature, time, and network information with configurable intervals and speed.

Audio Recordings

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.

Comparable System sound files:


The Viako Min Letter ML-45 barebones delivers much of what it promises, an attractive but slim box with hardware more than capable of producing a smooth media PC experience. The remote control is quite functional, the software can be customized to the point where you might never feel the need to touch a keyboard or mouse, and the VFD while not really that useful, is a nice addition. The only thing missing is an optical drive bay, something difficult to add to a 1.7″ tall enclosure. Sure there are many tech savvy media consumers that source most of their content from the internet and digitized backup archives, but the era of the shiny spinning disc is far from dead. Viako does offer larger Mini Letter cases and barebones with optical drive options but they’re twice as thick.

The foundation of the ML-45 is of course AMD’s E-350 APU which is a perfect fit for this type of system. It’s substantial faster than any Atom and its GPU is fully capable of rendering any video you can throw at it. There are other hardware combinations that are as capable, but AMD’s solution is the most balanced solution and very energy efficient. As a result, the ML-45 can be properly cooled, even on heavy load, with a reasonably low noise level. We were delighted to discover that the two tiny fans included were quite smooth sounding at lower speeds and that the fan control system of the included Giada motherboard was surprisingly versatile.

The only thing we didn’t like about the ML-45 was the egregious coil whine emitted by the board’s VRM circuitry. It was a constant annoyance throughout testing and only fully subsided when the system was powered down or put on heavy load. Due to its high frequency, it’s also difficult to drown out but does lessen with distance. If the ML-45 is placed next to a TV 8+ feet away (as it should be in an properly setup home theater room) it won’t be a problem, but as a close proximity system we simply can’t recommend it unless you’ve been robbed of your high frequency range by advanced age, head trauma, or genetic defect.

Our thanks to Viako
for the Mini Letter ML-45 LEAP E-350 sample.

* * *

Articles of Related Interest

Evo ECOPC: A Silent Nettop
Asus E35M1-M Pro: AMD Fusion Motherboard
Logic Supply SolidLogic Montivina Fanless Mini-ITX System
Zotac ZBOX HD-ND22: A CULV Nettop at last!
Samsung N220 Pine Trail Netbook
Asus EeeBox EB1501 ION Mini-PC

* * *

this article in the SPCR forums.

Silent PC Review is reader-supported. When you buy through links on our site, we may earn an affiliate commission. Learn More

Leave a Comment

Your email address will not be published. Required fields are marked *