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Gigabyte H55N-USB3: De Facto LGA1156 Mini-ITX Board?

With the limited and expensive selection of mini-ITX LGA1156 motherboards, the affordable Gigabyte H55N-USB3 has enough features and general appeal to charm most SFF PC builders.

October 23, 2010 by Lawrence Lee

Gigabyte H55N-USB
LGA1156 Mini-ITX Motherboard
Street Price

We consider the motherboard to be one of the most important components in a PC build. It is the heart of the system, not just because everything plugs into it, but because it determines what hardware can be used, essentially defining what it is and what it can ever be. Unlike most components, replacing a motherboard is no small alteration — in essence it changes the machine’s identity. When it comes to mini-ITX boards, if you want horsepower comparable to what you would typically find on larger form factors, the choices available are expensive and few.

For enthusiasts looking for the best desktop performance they can get in a diminutive size, Intel’s LGA1156 socket is obviously the one to consider. LGA1156 quad core processors compete very well against AMD’s quad and even hex core chips. At the lower end of the spectrum, Pentium/Core i3/Core i5 dual cores models are also capable and feature Intel GMA HD graphics which perform more or less on par with AMD’s current crop of integrated GPUs. Perhaps more importantly, the Intel chips have better energy efficiency and thus run cooler; this can be helpful in cramped mini-ITX cases.

The Gigabyte H55N-USB3 box.


At first glance, the Gigabyte H55N-USB3 is nothing to write home about. There are several elements that pop out of the box that try to catch your eye, but there isn’t anything that really stands out about the actual product. Except for the inclusion of USB 3.0, it has the standard features found on most H55 chipset boards. Appreciation comes later when you realize what else is out there — the number of mini-ITX LGA1156 boards is limited.

Its main competition comes from Intel’s DH57JG, and the Zotac H55-ITX-C-E (there is also an older H55-ITX A-E model that lacks USB 3.0) and as we discovered during our preliminary motherboard testing for our Silent Home Server Build Guide, there are caveats to both. The DH57JG delivers excellent power efficiency but a locked down BIOS and the H55-ITX-C-E offers extra features at the cost of very poor power efficiency. On paper, the H55N-USB3 seems to be a solid compromise, particularly as its US$105 street price is $15~$35 cheaper. Mini-ITX parts have inherent price premiums so being able to save a few bucks gives it a few points right off the bat.

Gigabyte H55N-USB3: Specifications
(from the product
web page
CPU 1. Support for an Intel® Core™ i7 series processor/Intel® Core™ i5 series processor/ Intel® Core™ i3 series processor in the LGA1156 package (Go to GIGABYTE’s website for the latest CPU support list.)
2. L3 cache varies with CPU
Chipset 1. Intel® H55 Express Chipset
Memory 1. 2 x 1.5V DDR3 DIMM sockets supporting up to 8 GB of system memory (Note 1)
2. Dual channel memory architecture
3. Support for DDR3 1666 (O.C.)/1333/1066/800 MHz memory modules
4. Support for non-ECC memory modules
5. Support for Extreme Memory Profile (XMP) memory modules

(Go to GIGABYTE’s website for the latest supported memory speeds and memory modules.)

Onboard Graphics Integrated in the Chipset: (Note 2)

1. 1 x D-Sub port
2. 1 x DVI-D port (Note 3) (Note 4)
3. 1 x HDMI port (Note 4)

Audio 1. Realtek ALC892 codec
2. High Definition Audio
3. 2/4/5.1/7.1-channel
4. Support for S/PDIF Out
LAN 1. 1 x Realtek RTL8111E chip (10/100/1000 Mbit)
Expansion Slots 1. 1 x PCI Express x16 slot, running at x16 (The PCIEX16 slot conforms to PCI Express 2.0 standard.)
Storage Interface Chipset: 1. 4 x SATA 3Gb/s connectors supporting up to 4 SATA 3Gb/s devices
2. 1 x eSATA 3Gb/s connector on the back panel supporting up to 1 SATA 3Gb/s device
USB Integrated in the Chipset:
1. Up to 8 USB 2.0/1.1 ports (4 on the back panel, 4 via the USB brackets connected to the internal USB headers)

NEC D720200F1 chip:
1. Up to 2 USB 3.0/2.0 ports on the back panel

* USB 3.0 10x performance is a maximum theoretical value. Actual performance may vary by system configuration.

Internal I/O Connectors 1. 1 x 24-pin ATX main power connector Connectors
2. 1 x 4-pin ATX 12V power connector
3. 4 x SATA 3Gb/s connectors
4. 1 x CPU fan header
5. 1 x system fan header
6. 1 x front panel header
7. 1 x front panel audio header
8. 1 x S/PDIF Out header
9. 2 x USB 2.0/1.1 headers
10. 1 x debug card header
11. 1 x chassis intrusion header
12. 1 x clearing CMOS jumper
Back Panel Connectors 1. 1 x PS/2 keyboard/mouse port Connectors
2. 1 x D-Sub port (Note 2)
3. 1 x DVI-D port (Note 2)(Note 3) (Note 4)
4. 1 x optical S/PDIF Out connector
5. 1 x HDMI port (Note 2)(Note 4)
6. 4 x USB 2.0/1.1 ports
7. 2 x USB 3.0/2.0 ports
8. 1 x eSATA 3Gb/s connector
9. 1 x RJ-45 port
10. 6 x audio jacks (Center/Subwoofer Speaker Out/Rear Speaker Out/ Side Speaker Out/Line In/Line Out/Microphone)
I/O Controller 1. iTE IT8720 chip
H/W Monitoring 1. System voltage detection
2. CPU/System temperature detection
3. CPU/System fan speed detection
4. CPU fan speed control (Note 5)
BIOS 1. 2 x 64 Mbit flash
2. Use of licensed AWARD BIOS
3. Support for DualBIOS™
4. PnP 1.0a, DMI 2.0, SM BIOS 2.4, ACPI 1.0b
Unique Features 1. Support for @BIOS
2. Support for Q-Flash
3. Support for Xpress BIOS Rescue
4. Support for Download Center
5. Support for Xpress Install
6. Support for Xpress Recovery2
7. Support for EasyTune (Note 6)
8. Support for Dynamic Energy Saver™ 2
9. Support for Smart 6™
10. Support for Auto Green
11. Support for ON/OFF Charge
12. Support for Q-Share
Bundle Software 1. Norton Internet Security (OEM version)
Operating System 1. Support for Microsoft® Windows 7/Vista/XP
Form Factor 1. Mini-ITX Form Factor; 17.0cm x 17.0cm
Remark 1. Due to different Linux support condition provided by chipset vendors, please download Linux driver from chipset vendors’ website or 3rd party website.
2. Most hardware/software vendors no longer offer support for Win9X/ME/2000/XP SP1/SP2. If drivers are available from the vendors, we will update them on the GIGABYTE website.
3. Minimum 200 Watts Power supply is suggested on this model.
Notes (Note 1) Due to Windows 32-bit operating system limitation, when more than 4 GB of physical memory is installed, the actual memory size displayed will be less than 4 GB.
(Note 2) To use the onboard D-Sub, DVI-D, and HDMI ports, you must install an Intel CPU with integrated graphics.
(Note 3) The DVI-D port does not support D-Sub connection by adapter.
(Note 4) You can use only one of the onboard digital graphics ports (HDMI and DVI-D) for output when in the BIOS Setup program or when during the POST screens.
(Note 5) Whether the CPU fan speed control function is supported will depend on the CPU cooler you install.
(Note 6) Available functions in EasyTune may differ by motherboard model.


A board’s layout is important as the positioning of components can dictate
compatibility with other products like third party heatsinks and also disrupt
airflow, making a system more thermally challenging, those this latter aspect is less important on a mini-ITX product.

The short distance between a potential graphics card and the CPU makes choosing a third party heatsink difficult. For smaller cases, our forum dwellers prefer the Thermalright AXP-140. In larger cases, anything that does not extend beyond the mounting lines on the board is suitable, like the Scythe Samurai ZZ.


Cooling may be an issue on the H55N as the PCH heatsink is rather small and a nameplate covers the top. There is also nothing helping cool the voltage regulation circuitry to the left of the CPU socket.


From another angle.


The back panel includes DVI, HDMI, S/PDIF, eSATA, and USB 3.0 (blue) connectors; it’s a fairly standard assortment. Please note that the video outputs only work with CPUs supporting Intel GMA HD graphics, i.e. dual core LGA1156 models.


For enthusiasts, the options available within the BIOS can turn
a good board into a great one. The ability to manipulate frequencies, voltages,
and fan control settings vary depending on the hardware and the amount of trust
placed in the users’ hands by the manufacturer.

Frequency settings.

Voltage settings.

PC Health Status settings.


BIOS Summary: Gigabyte H55N-USB3
CPU Clock
100 to 600 MHz
CPU Core Voltage
0.50000V to 1.90000V in in 0.00625V increments
QPI/VTT Voltage
1.050V to 1.490V in varying increments (1.100V default)
PCH Voltage 0.950V to 1.500V (1.050V default)
Memory Voltage
1.30V to 2.60V in varying increments
Memory Multiplier
6, 8, 10
Memory Timing Control
Integrated Graphics
GPU Clock 0 to 2000 MHz
GPU Voltage
0.200V to 1.800V in varying increments (1.350V default)
Fan Control
Smart Fan Control
Enabled / Disabled
Smart Fan Mode
Auto / PWM / Voltage

Enthusiasts entering the H55N’s BIOS will be greeted with a incredibly liberal level of customization for a mini-ITX motherboard. The core voltage can be undervolted down to 0.5V or overvolted up to 1.9V. Wide ranges are available for all voltages, including the memory and onboard GPU. Frequency control is similarly unbound, going as high as one would dare attempt.

The only disappointment is the lack of customizable Smart Fan settings. The automatic fan control can be either turned on or off, but aside from that, there’s nothing you can do to alter fan speed behavior until you boot into an operating system. In addition, only one of the two fan headers can be controlled.


Test Setup:

Testbed device listing.

Measurement and Analysis Tools

H.264/VC-1 Video Test Suite

H.264 and VC-1 are codecs commonly used in high definition movie videos on
the web (like Quicktime movie trailers and the like) and also in Blu-ray discs.
To play these clips, we use Cyberlink PowerDVD.

1080p | 24fps | ~10mbps
Rush Hour 3 Trailer 1
is a H.264 encoded clip inside an
Apple Quicktime container.


1080p | 24fps | ~8mbps
Coral Reef Adventure Trailer
is encoded in VC-1 using the
WMV3 codec commonly recognized by the “WMV-HD” moniker.


1080p | 24fps | ~33mbps
Blu-ray: Disturbia is a short section (chapter
4) of the Blu-ray version of Disturbia, the motion picture, played
directly off the Blu-ray disc. It is encoded with H.264/AVC.


1080p | 24fps | ~36mbps
Blu-ray: Becoming Jane is a short section
(chapter 7) of the Blu-ray version of Becoming Jane, the motion
picture, played directly off the Blu-ray disc. It is encoded with

x264/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 clip was taken from a full length movie;
the most demanding one minute portion was used. We use Media Player Classic
Home – Cinema to play it as its default settings allow it to use DXVA
(DirectX Video Acceleration) by default.

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.


Estimating DC Power

The following power efficiency figures were obtained for the
Seasonic SS-400ET used in our test system:

Seasonic SS-400ET Test Results
DC Output (W)
AC Input (W)

This data is enough to give us a very good estimate of DC demand in our test
system. We extrapolate the DC power output from the measured AC power input
based on this data. We won’t go through the math; it’s easy enough to figure
out for yourself if you really want to.

Testing Procedures

If available, the latest motherboard BIOS is installed prior to testing and
256MB is allocated to the integrated graphics core, if applicable. Certain services/features
like Indexing, Superfetch, System Restore, and Windows Defender are disabled
to prevent them from causing spikes in CPU/HDD usage. We also make note if energy
saving features like Cool’n’Quiet/SpeedStep or S3 suspend-to-RAM do not function

Our main 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 IGP, we use FurMark, an OpenGL
benchmarking and stability testing utility. Power consumption during playback
of high definition video is also recorded.

Our video test suite features a variety of high definition video clips. If
the video (and/or audio) skips or freezes, we conclude the board’s IGP (in conjunction
with the processor) is inadequate to decompress the clip properly. High CPU
usage is indicative of poor video decoding ability on the part of the integrated
graphics subsystem.

Detailed DC Power Consumption

System Power Consumption: Idle/Load (DC)
Test State
Idle / Load Voltage*
CPU Load
CPU + GPU Load
Intel DH55TC
Intel DH57JG
0.920V / 1.136V
not tested
Gigabyte H55N-USB3 (-0.0625V)
0.912V / 1.104V
Gigabyte H55N-USB3 (Stock)
0.952V / 1.216V
Asus P7H55D-M EVO [mATX]
0.968V / 1.144V
Zotac H55-ITX-C-E
1.056V / 1.320V
* according to CPU-Z

The H55N is a bit of a mixed bag. It’s more energy efficient when idle compared to the Asus P7H55D-M, but less so when on load, especially when the GPU is stressed in addition to the CPU. When the GPU was added to the mix, it suffered from the same inefficiency as the Zotac H55-ITX, albeit to a lesser degree. Thankfully this won’t be an issue for most end-users unless they plan on gaming using Intel GMA HD graphics.

The Intel models seem to have a big advantage as none of the third party boards came even remotely close in power consumption. Even when we undervolted the H55N to the point where the reported core voltage was lower than on the Intel DH57JG, the system still ended up consuming an extra 10W DC when idle.

CPU+VRM Power Consumption: Idle/Load (DC)
Test State
Idle / Load Voltage*
CPU Load
CPU + GPU Load
Intel DH55TC
Gigabyte H55N-USB3 (-0.0625V)
0.912V / 1.104V
Gigabyte H55N-USB3 (Stock)
0.952V / 1.216V
Asus P7H55D-M EVO [mATX]
0.968V / 1.144V
Zotac H55-ITX-C-E
1.056V / 1.320V
* according to CPU-Z

Our CPU+VRM measurements were taken from the
AUX12V connector with the help of a pair of digital multimeters and an in-line
0.01 ohm shunt resistor and represents the approximate draw of the +12V line by the processor including inefficiencies lost to the VRMs.
In some cases, this can help us narrow down the causes of power consumption
differences between boards.

In this case, it’s hard to make sense of the data. The Asus P7H55D-M and Zotac H55-ITX both pull a lot more from the +12V line when idle than the other boards compared above, but they draw even with the ultra-efficient Intel DH55TC when placed on load. The H55N uses less both when idle and on load, but overall system power favors the DH55TC by a heavy margin.

System Power Consumption: Video Playback (DC)
Test Clip
Zotac H55-ITX-C-E
Asus P7H55D-M EVO
Gigabyte H55N-USB3
Intel DH55TC
Rush Hour
Coral Reef
(Blu-ray H.264)
Becoming Jane
(Blu-ray VC-1)
not tested

Intel GMA HD graphics are built into dual core LGA1156 chips, making high definition video rendering a non-issue. However, power consumption during playback does vary from the board to board, and in this case the H55N was only slightly more frugal with power than the boards from Asus and Zotac.


To test the board’s cooling, we ran the CPU fan at a fixed speed (~900 RPM)
using an external power source and ran Prime95 and FurMark. The system was left
to stew until temperatures stabilized. Temperatures were taken with a spot thermometer
and the results were for the hottest portion of the heatsink.

Heatsink Temperatures
Intel DH55TC
44°C (bare)
Asus P7H55D-M EVO
Zotac H55-ITX-C-E
Gigabyte H55N-USB3
70°C (bare)
Thermalright MUX-120 with stock fan @ ~900 RPM.
Ambient temperature: 22°C.

In addition to the lack of WiFi and two fewer SATA ports, the H55N-USB3 has one more deficiency compared to the Zotac H55-ITX-C-E: a complete lack of VRM cooling. On full load, most of the MOSFETs next to the CPU socket measured above 60°C, while the hottest one we could find was a toasty 70°C, 20~25° hotter than other H55 boards we’ve tested.

Fan Control

During our cooling test we also monitored fan speeds and temperatures using SpeedFan. Fans were connected to the onboard headers and if the fans did not reach their maximum rated speeds, we lowered the CPU fan speed to induce higher temperatures.

Fan Control
(2500 RPM)
(1600 RPM)
Min. Fan Speed
600 RPM
1580 RPM
Trigger Temp.
Max. Fan Speed Temp.

During our test, the H55N kept a 2500 RPM PWM fan at 600 RPM when core temperatures were under 20°C. Once past this point the fan speed increased linearly until topping out at approximately 68°C. With such a wide temperature range between the minimum and maximum fan speeds, the increase in fan speed was pleasantly gradual. The second fan header could not be controlled and supplied a full 12V to fans connected to it.

EasyTune Smart Fan settings.

While there was nothing we could do in the BIOS to customize the automated fan control, in Windows, Gigabyte’s EasyTune software allowed us to adjust how the fan behaved.

SpeedFan screen with correlations added to the sensor titles.

We are happy to report that SpeedFan works on the H55N without issue. Some of the voltages were out of whack and there were a pair of temperature sensors that were stuck at the same reading, but it was otherwise functional. There are two speed controls available for the CPU fan header, one for voltage control and one for PWM. To enable full fan control, go to the Advanced Configuration menu, find the chip “IT8720F” and change its PWM modes to “Software Controlled.”


For an LGA1156 board, the Gigabyte H55N-USB3’s energy efficiency when idle and on CPU load is smack dab in the middle, only impressive if you ignore the boards from Intel which apparently run only partially on electricity with the slack being picked up by what we can only assume is fairy dust. It’s a good choice for a multipurpose or gaming machine, but is less so for a system that needs to stay on for long periods of time like a server. The H55N also suffers from the same unusual high power draw we encountered on the Zotac H55-ITX when Intel GMA HD graphics are put on full load, but luckily that scenario is unlikely to play out often for most users.

The options available in the BIOS were a pleasant surprise. We have not seen a mini-ITX board with such a wide range of frequency and voltage settings. In theory, this makes it a daring enthusiast’s dream for overclocking… but the lack of VRM cooling may bring you a step back. The VRMs around the CPU socket get very hot and will become increasingly inefficient and prone to damage or failure as they are pushed harder. With enough airflow from a down-blowing CPU cooler fan, this could be overcome, but then you may be sacrificing low noise for higher clock speed. At the other end of the spectrum, various components can be undervolted heavily, but giving a little less juice to the CPU only saved power on load, not when idle.

Compared to its main competition, the H55N-USB3 is middle-of-the-road in terms of features. It lacks the six SATA ports and Wireless-N adapter offered by the Zotac H55-ITX-C-E, but includes a USB 3.0 controller missing from the Intel DH57JG. If it was a microATX motherboard, the Gigabyte H55N-USB3 would be lost in the crowd. However, with so few mini-ITX boards of its kind, the reasonably modern feature-set and affordability makes it shine. With a street price of only US$105, it is quite affordable and has general appeal, making it our recommended starting point for a mini-ITX LGA1156 board.

Gigabyte H55N-USB3

* Low idle power (for a non-Intel board)
* Lots of frequency/voltage options in BIOS
* USB 3.0
* Affordable


* High IGP load power consumption
* Lack of VRM cooling

Our thanks to Gigabyte
for the H55N-USB3 sample.

The Gigabyte H55N-USB3 is Recommended by SPCR.

* * *

Articles of Related Interest
Silent Home Server Build Guide
Zotac H55-ITX-C-E: Stacked LGA1156 Mini-ITX Motherboard
890GX Chipset

Asus P7H55D-M EVO LGA1156 microATX Motherboard
Intel Core i5-661: A 32nm CPU with
Integrated Graphics

Gigabyte MA785GPMT-UD2H 785G Motherboard

* * *

this article in the SPCR forums.

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