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Asus P5Q-EM G45 mATX motherboard

Asus P5Q-EM:

November 18, 2008 by Lawrence Lee

Product Asus P5Q-EM

Intel LGA775 Motherboard
Manufacturer ASUSTeK
Street Price US$140

Asus has a tradition of producing quality, feature-rich motherboards.
The P5E-VM HDMI was
one of their best — an Intel LGA775 mATX board based on the G35 chipset.
With so many features it made an excellent ATX replacement and stood alone in
its class for almost a year. Now, poised to replace it is the Asus P5Q-EM.
Sporting a similar feature-set, but based around the new G45 chipset, it has
some big shoes to fill.

Our first experience with Intel's G45 chipset was very positive. The DG45FC, Intel's mini-ITX adaptation of the chipset, proved to be very capable
and extremely power efficient. Its form factor, however, is very restrictive; it does not even support all of Intel's current processors — you
cannot use a quad core with it or anything with a TDP over 65W. For those
wanting a little more versatility, the microATX form factor is ideal. The question
is: does G45 translate as well to mATX?

Asus' Intel motherboards typically ship with a glossy blue box.

Box contents.

Asus P5Q-EM: Specifications (from the
product web page
CPU Intel® Socket 775 for
Intel® Core™2 Extreme/Core™2 Quad/ Core™2 Duo/Pentium®
dual-core/Celeron® dual-core /Celeron® Processors

Compatible with Intel® 05B/05A/06 processors

Intel® 45nm Multi-Core CPU support

*Refer to for Intel CPU support list
Chipset Intel® G45 / ICH10R
with Intel® Fast Memory Access (FMA) Technology
Front Side Bus 1600/1333/1066/800 MHz
Memory 4 x DIMM, Max. 16 GB, DDR2
1066(O.C.)/800/667 Memory

Dual Channel memory architecture

When installing total memory of 4GB capacity or more, Windows 32-bit operation
system may only recognize less than 3GB. Hence, a total installed memory
of less than 3GB is recommended.
Expansion Slots 1 x PCIe 2.0 x16

2 x PCIe x1

1 x PCI
VGA Integrated Intel® Graphics
Media Accelerator X4500HD

Multi-VGA output support: HDMI, DVI-D and RGB

Supports HDMI with max. resolution 1920 x [email protected]

Supports DVI with max. resolution 1920 x [email protected]

Supports RGB with max. resolution 2048 x [email protected]

Maximum shared memory of 1849 MB

Supports Microsoft® DirectX® 10, OpenGL® 2.1, Pixel Shader 4.0
Storage Southbridge

6 xSATA 3 Gb/s ports

Intel® Matrix Storage Technology Support RAID 0,1,5,10

Marvell® 6102

1 x UltraDMA 133/100/66 for up to 2 PATA devices
LAN Realtek® 8111C PCI-E
Gigabit LAN controllers, featuring AI Net2
Audio Realtek® ALC 1200 8
-Channel High-Definition Audio CODEC

- Support Jack-detection, Multi-streaming

- ASUS Noise Filtering

- DTS Surround Sensation UltraPC
IEEE 1394 Agere® L-FW3227 controller
supports 2 x 1394a ports (one at midboard; one at back panel)
USB 12 USB 2.0 ports (6 ports
at mid-board, 6ports at back panel)
ASUS Unique Features ASUS Power Saving Solution:

- ASUS EPU-4 Engine

- AI Nap

ASUS Exclusive Feature:

- ASUS Express Gate

ASUS Quiet Thermal Solution:

- ASUS Fanless Design

- ASUS Fan Xpert

ASUS Crystal Sound:

- ASUS Noise Filtering


- ASUS Q-Connector

- ASUS O.C. Profile

- ASUS CrashFree BIOS 3

- ASUS EZ Flash 2
Overclocking Features Precision Tweaker 2:

- vCore: Adjustable CPU voltage at 0.00625V increment

- vDIMM: 45-step DRAM voltage control

- vChipset (NB): 30-step chipset voltage control

- vCPU PLL: 35-step CPU PLL voltage control

- vFSB Termination: 25-step reference voltage control

SFS (Stepless Frequency Selection)

- FSB tuning from 200MHz up to 800MHz at 1MHz increment

- PCI Express frequency tuning from 100MHz up to 180MHz at 1MHz increment

Overclocking Protection:

- ASUS C.P.R.(CPU Parameter Recall)
Special Features ASUS MyLogo 2™
Back Panel I/O Ports 1 x PS/2 Keyboard/Mouse
combo port

1 x Optical S/PDIF output

1 x D-Sub port

1 x DVI port

1 x HDMI port

1 x IEEE1394a

1 x LAN (RJ45) port

6 x USB 2.0/1.1

8-channel Audio I/O
Internal I/O Connectors 3 x USB connectors support
additional 6 USB ports

1 x Floppy disk drive connector

1 x IDE connector

1 x COM connector

6 x SATA connectors

1 x CPU Fan connector

1 x Chassis Fan connector

1 x Power Fan connector

1 x IEEE1394a connector

Front panel audio connector

1 x S/PDIF Out Header

Chassis Intrusion connector

CD audio in

24-pin ATX Power connector

1 x 4-pin ATX 12V Power connector

System Panel (Q-Connector)
PnP, DMI2.0, WfM2.0, SM BIOS 2.4, ACPI 2.0a, ASUS EZ Flash 2, ASUS CrashFree
Manageability WOL by PME, WOR by PME,
WOR by Ring, Chassis Intrusion, PXE
Accessories 1 x UltraDMA 133/100/66

1 x FDD cable

3 x Serial ATA cables

2 x Serial ATA power cable for 3 devices

1 x eSATA bracket

I/O Shield

User's manual

3 in 1 Q-connector
Support Disc Drivers

ASUS Express Gate


ASUS Update


Anti-virus software (OEM version)

Image-Editing Suite
Form Factor uATX Form Factor

9.6 inch x 9.6 inch ( 24.4 cm x 24.4 cm )


A board's layout is important in several regards. The positioning of components
can dictate compatibility with other products (third party heatsinks mainly)
and also ease of installation. Poorly placed power connectors can also disrupt
airflow and thus make the system more thermally challenging.


The PCB layout is pretty clean with all the major power and interface connectors
on the edges. The CPU socket is clear of any obstructions and is a fair distance
away from the top edge of the board, making it a prime candidate for third party
cooling. The board has 6 SATA ports, a single IDE channel, a floppy connector,
and 3 fan headers.

At an angle.

The most notable feature are the chipset heatsinks as their bright blue
color and angled-fins stand out from the black PCB. The northbridge cooler is
surprisingly modest, extending only 26mm up from the PCB surface. There is no
cooling provided for the VRMs, but all the boards' capacitors are of the solid-state

Back panel.

The rear I/O panel is well stocked with HDMI, DVI and S/PDIF ports, allowing
for digital video and audio connectivity. There is also a FireWire port and
eSATA is available via an included adapter bracket.


BIOS options on mATX boards are typically very spartan. The
presence of an IGP and the more limited cooling associated with an mATX platform
makes manufacturers nervous about allowing users the ability to customize
their clock/voltage settings.

Notable Available BIOS Adjustments
CPU FSB 200 to 800Mhz in 1Mhz increments
CPU Voltage 0.85000V to 1.60000V in 0.00625V increments
Memory Frequency Varies depending on processor
Memory Timings Advanced
Memory Voltage 1.80V to 2.70V in 0.02V increments
Northbidge Voltage 1.10V to 1.70V in 0.02V increments
PCI SATA Voltage 1.50V to 1.80V in 0.10V increments
Video Memory Size 32MB, 64MB, 128MB + 128MB/256MB DVT

The BIOS controls in the P5Q-EM are impressive.
Frequency and voltage ranges go beyond the needs of most sane enthusiasts. CPU, memory, and northbridge voltages can be changed in minute intervals
allowing for precision control.

"The "Ai Tweaker" menu is filled with numerous settings
to tweak to your hearts' desire.

More "Ai Tweaker."

"Hardware Monitor."

Fan control settings are available in the "Hardware Monitor"
menu. The board can control the CPU and Chassis fan header, but they have
only two settings: Silent and Turbo.


Test Setup:

Measurement and Analysis Tools

Our main test procedure is designed to determine the overall system power
consumption at various states (measured using a Seasonic Power Angel), and to
test the integrated graphics' proficiency at playing back high definition videos.
Standard HD-DVD and Blu Ray discs can be encoded in three different codecs by
design: MPEG-2, H.264/AVC and VC-1. MPEG-2 has been around for a number of years
and is not demanding on modern system resources. H.264 and VC-1 encoded videos
on the other hand, due to the amount of complexity in their compression schemes,
are extremely stressful and will not play smoothly (or at all) on slower PCs,
especially with antiquated video subsystems.

We use a variety of H.264/VC-1 clips encoded for playback on the PC. The clips
are played with PowerDVD 8 and a CPU usage graph is created by the Windows Task
Manger for analysis to determine the approximate mean and peak CPU usage. High
CPU usage is indicative of poor video decoding ability on the part of the integrated
graphics subsystem. If the video (and/or audio) skips or freezes, we conclude
the board's IGP (in conjunction with the processor) is adequate to decompress
the clip properly.

SpeedStep was enabled and the following features/services were disabled during
testing to prevent spikes in CPU/HDD usage that are typical of fresh Vista installations:

  • Windows Sidebar
  • Indexing
  • Superfetch

Video Test Suite

1080p | 24fps | ~10mbps
Rush Hour 3 Trailer 1
is encoded in H.264 with Apple Quicktime.

1080p | 24fps | ~7.5mbps
Coral Reef Adventure trailer
is encoded in VC-1 using the
WMV3 codec (commonly recognized by the moniker, "HD WMV").

720p | 60fps | ~12mbps
WVC1: Microsoft Flight Simulator X trailer
is encoded in VC-1. It is encoded using the Windows Media Video 9
Advanced Profile (aka WVC1) codec — a much more demanding implementation
of VC-1.

1920x1080 | 24fps | ~19mbps
WVC1: Drag Race is a recording of a scene from
network television re-encoded with TMPGEnc using the WVC1 codec. It
is the most demanding clip in our test suite.


Our test system is fairly basic, featuring a Core 2 Duo E7200 (45nm, 65W) cooled
by an Arctic Cooling Alpine 7 Pro connected to a variable DC fan controller
so the fan's power draw does not come into play, and a single stick of Corsair
memory. The rest of our test test platform consists of an Asus Blu-ray drive,
a 5400RPM notebook hard drive, and an OEM Seasonic 400W power supply. The operating
system used is Vista Home Premium SP1 (32-bit).

P5Q-EM with CPU, memory and heatsink installed.

We tested the board with the CPU at stock settings with SpeedStep enabled and
underclocked/undervolted to the minimum stable settings the BIOS would allow:
1.2Ghz at 0.850V.

Test Results: Asus P5Q-EM
Test State
E7200 @ 2.53Ghz (EIST)
E7200 @ 1.2Ghz (0.850V)


System Power


System Power
Sleep (S3)
Rush Hour
Coral Reef
Flight Sim.
Drag Race
Prime95 + ATITool

At stock settings, the system idled at 44W, drew in the mid 50s during video
playback, and about 75W on load. Stressing the IGP did not significantly increase
power consumption. The X4500 graphics chip did not have any problems with our
test suite, passing it with flying colors. The CPU usage was relatively low
during video playback but the processor was running at its full clock speed
most of the time according to CPU-Z.

At 1.2Ghz and 0.850V, power consumption was 3W less at idle, about 6W during
video playback and approximately 22W lower on full load. Despite the extremely
low clock speed (none of Intel's desktop dual core processors are less than
1.6Ghz), our entire video test suite played smoothly without any problems.

System Power Consumption Comparison
Test State
Intel DG45FC

(G45 mITX)
Asus P5Q-EM

(G45 mATX)
Asus P5E-VM

(G35 mATX)
Rush Hour
Coral Reef
Flight Sim.
Drag Race
Prime95 + ATITool

The power consumption of the board was somewhat disappointing after our experience
with the Intel DG45FC,
Intel's mini-ITX G45 motherboard. The DG45FC was extremely power efficient,
with an especially impressive idle power reading. The P5Q-EM idled almost 10W
higher. Compared to Asus' G35 motherboard, the P5E-VM
, it was only 3W lower at idle, and during video playback and full
load, the power draw was nearly identical.

The P5Q-EM and DG45FC use the same chipset, but the P5Q-EM has a few more devices
to power, including a PCI-E 16x slot, two PCI slots, and a FireWire controller.
It should also be noted that the DG45FC may have less versatile power regulation
circuitry as it does not support Intel's quad core CPUs. Manufacturers tend
to make boards with more power phases for high wattage processors, sometimes resulting
in lower efficiency when the power draw is low.


When it comes to customizable control, SpeedFan is our application of choice.
If properly supported, it can be configured to raise/lower multiple fan speeds
to designated limits when any specified temperature threshold is breached.

SpeedFan main screen, edited with correlations.

SpeedFan duplicates most of the functionality of the Asus PC Probe application,
except for the +5V and +12V readings. Unfortunately, it is only capable of controlling
the Chassis fan header — the Speed01 and Speed02 controls are tied to the
same header. To enable fan control, set PWM modes 2 and 4 in the Advanced menu
to "Manual PWM Control."

Fan Xpert.

As an alternative, the Asus Fan Xpert utility is surpringly versatile. You can
set preset profiles for the CPU and Chassis fans, some of which are not available
in the BIOS menu. It also illustrates exactly how each setting behaves with
a small CPU temperature vs. fan speed graph.

Fan Xpert custom profile settings.

There is also a User profile which can be set with your own custom parameters.
On the graph there are three temperature/fan speed points that can be altered
to adjust the curve however you see fit.

We tested the fan control system by connecting the fan on the CPU cooler to
a variable DC fan controller set to only 4V and proceeded to stress the processor
using Prime95. A 92mm Scythe Kama Flow 2500RPM PWM fan was connected to the
CPU fan header and a Scythe 80mm Kama Flex 1500RPM fan to the Chassis fan header
and their speeds were monitored using SpeedFan. We found that the fans ramped
up exactly according to the parameters reported by the Fan Xpert utility.


With very effective third party heatsinks on the market, and many low power
CPUs available, overclocking can improve performance without
compromising the noise level of a silent PC.

A simple overclocking investigation was conducted with the CPU multiplier set
to 6x and RAM to its lowest speed with an extra 0.3V. The CPU frequency was
increased in increments of 5Mhz/10Mhz until the system failed a 5 minute
run of Prime95 with ATITool 3DView running simultaneously or failed to boot
or showed other signs of instability. We then maximized the multiplier and increased
the CPU voltage to a stable level for our final overclock.

2.97Ghz: the maximum overclock on the P5Q-EM.

The highest stable FSB we achieved was 330Mhz for a maximum overclock of 2.97Ghz,
or 24% above stock. At 335Mhz and above, ATITool would crash, indicating a problem
with the IGP. Note that this result was obtained without adjusting the northbridge
or other voltages, so it's possible the P5Q-EM can overclock further. These
are simply the out-of-the-box results.


To test the cooling on the board, we lowered the CPU cooling fan's voltage
to 6V to reduce the amount of top-down airflow the nearby components received.
We then stressed the system with Prime95 and ATITool and whipped our our handy
IR thermometer to check the results.

After about 20 minutes of load, the hottest point on the northbridge heatsink
registered 58°C, while the southbridge heatsink read 47°C. The hottest
MOSFETs around the CPU socket did not exceed 60°C — most of them were
well below that. These results are quite good compared to previous boards, and
especially surprsing given the size of the northbridge cooler, and the lack
of VRM cooling.


To get a rough estimate of how well the P5Q-EM's onboard video plays games,
we ran 3DMark05/06. As synthetic benchmarks they have limited value, but they
give you a rough idea of how well it performs.

3D Performance: Futuremark Comparison

Intel DG45FC (2.13Ghz)

(GMA X4500 IGP)
Asus M3N78 Pro

(Geforce 8300 IGP)
Asus P5Q-EM (2.53Ghz)

(GMA X4500 IGP)
Gigabyte MA78GM-2SH

(Radeon HD 3200 IGP)
Gigabyte MA78GM-2SH

(Radeon HD 3450 256MB)
All results with 2GB of system RAM and 256MB of VRAM
assigned (if applicable). Intel systems in blue, AM2 (X2 4850e) systems in green.

Our previous benchmarks using the GMA X4500 IGP on the DG45FC were obtained
with the 2.13Ghz Core 2 Duo E6400. The P5Q-EM was tested with an E7200 and the
extra 400Mhz gave it a nice boost in performance, registering an extra 500 points
in 3DMark05 and 190 points in 3DMark06. This is more or less equivalent to the
Asus M3N78 Pro (Geforce
8300) when paired with the 2.5Ghz AMD X2 4850e processor. It's still a long
way off compared to AMD's mainstream 780G IGP or a low budget discrete card
like the Radeon HD 3450.


HDMI signal.

The board's HDMI output worked flawlessly with our Asus
LCD monitor at 1920x1200 resolution. There was no overscanning
or other video issues — it looked identical to the DVI output. The audio functioned
perfectly as well, sending stereo sound to the monitor's built-in speakers
without any fiddling with the sound settings.


We found G35 chipset Asus P5E-VM HDMI to be an excellent motherboard
with a quality, feature rich design. The P5Q-EM is essentially the same board, advanced one chipset generation.
The two boards come with similar feature sets
and even the layout is nearly identical. The chipset, heatsinks, and the inclusion
of an eSATA adapter bracket are essentially the only changes from the P5E-VM to the P5Q-EM.

The X4500 IGP handles video playback with ease and efficiency. Even with a
Core 2 Duo underclocked to only 1.2Ghz, it manages to get through our video test
suite gracefully. Its 3D performance, like previous Intel incarnations,
is severely lacking. It's not much of an improvement over X3500.
However, given that the pricing of the P5Q-EM and P5E-VM are similar, there
is no reason not to go with the newer model.

The Asus Fan Xpert utility deserves praise. It's one of the best fan control systems we've seen on any motherboard. It works precisely as intended, which makes it exceptional. With PWM fans becoming commonplace, a utility like Fan Xpert makes the task of fine-tuning for the best balance of quiet and cooling a breeze.

The power consumption of the board is substantially higher than the Intel mini-ITX G45 board, the DG45FC.
That little G45 board reached record low idle power for an Intel board in our lab — a full 10W less than
the G35 motherboards we tested. In contrast, the P5Q-EM delivers almost no improvement over the P5E-VM HDMI,
so it's obvious that the G45 chipset wasn't the reason for the mITX DG45FC's power draw, but rather, the absence of other devices that draw power on bigger boards.
Still, we have a step improvement in performance without paying for it with greater power consumption. The Asus P5Q-EM is a fine socket 775 mATX board suitable for just about any role short of extreme multi-videocard gaming.


* Efficient video playback

* Undervolts well

* Feature-set, connectivity

* Chipsets/VRMs runs cool

* Price

* Limited 3D performance

Our thanks to ASUSTeK
for the Asus P5Q-EM sample.

* * *

Articles of Related Interest

Asus M3A78-T: AMD's IGP Gets Another Boost

DG45FC: Loaded LGA775 Mini-ITX Board

DG35EC: G35 mainstream mATX board

D945GCLF m-ITX: Atom For The Desktop

NF610i-ITX: A Compact Core 2 Solution

Gigabyte GA-MA74GM-S2: AMD 690G, Take 2

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