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

The oddly named M3A78-T is yet another in a recent line of ATX boards from Asus with onboard graphics. Along with the 790GX northbridge chip, the M3A78-T also features the improved SB750 southbridge that brings RAID-5 support to AMD’s SATA controller for the first time. The board also has a whack of other features including CrossFire and Hybrid CrossFireX, FireWire, eSATA, HDMI and S/PDIF outputs. This isn’t your grandmother’s motherboard.

October 25, 2008 by Lawrence Lee

Product Asus M3A78-T
AM2/AM2+ Motherboard
Manufacturer ASUSTeK
Street Price US$150-160

Earlier this year, the release of AMD’s
780G chipset
brought new respectability to onboard graphics. The HD 3200
took 3D performance in an IGP to unprecedented levels, provides excellent video
playback, and did it all without breaking the bank. While AMD struggle to keep
up with Intel CPUs, an affordable and functional budget chipset
allows AMD to compete successfully in the value market segment. In fact, Intel’s IGPs still can’t match the 780G for 3D performance.

Not content to sit on their lead, AMD recently released the 790GX chipset featuring
a further improved IGP, the HD 3300. While the chip innards have changed little from the 3200,
its die has shrunk to a smaller 55nm size, it has a significant 200Mhz
bump in core clock speed, and it can take advantage of Sideport memory.
Sideport is a single chip of fast DDR3 memory integrated
for the purpose of speeding up the GPU and making it less necessary to tap large amounts of system memory for its use. The amount of Sideport memory depends
on the board — the Asus M3A78-T has 128MB of Sideport
memory running at 1333Mhz.

Another shiny motherboard box from Asus.

The oddly named M3A78-T is yet another in a recent line of ATX boards
from Asus with onboard graphics. Along with the 790GX northbridge chip, the
M3A78-T also features the improved SB750 southbridge that brings RAID-5 support
to AMD’s SATA controller for the first time. The board also has a whack of other
features including CrossFire and Hybrid CrossFireX, FireWire, eSATA, HDMI and
S/PDIF outputs. This isn’t your grandmother’s motherboard.

The package contents. Nothing out of the ordinary.


Asus M3A78-T: Specifications (from the
product web page
AMD Socket AM2+ / AM2 Processors
AMD Phenom™ FX / Phenom / Athlon™ / Sempron™
AMD Cool’n’Quiet™ Technology
Support CPU up to 140W
AMD 790GX/SB750
System Bus
Up to 5200 MT/s HyperTransport™
3.0 interface for AM2+ CPU
2000 / 1600 MT/s for AM2 CPU
4 x DIMM, Max. 16 GB, DDR2
1066/800/667 ECC,Non-ECC,Un-buffered Memory
Dual Channel memory architecture
*Due to AMD CPU limitation, DDR2 1066 is supported by AM2+ CPU for one DIMM
per channel only.
**Please refer to www.asus.com or user manual for Memory QVL(Quality Vender
***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
3 x PCIe x16 (Support PCIe
2.0 / 1.0 Architecture ) (Dual x8 or Dual x16/x4; Triple x8/x4/x8)
1 x PCIe x1
2 x PCI 2.2
Integrated ATI Radeon™
HD 3300 GPU
SidePort Memory – onboard 128MB DDR3 1333 memory
Supports HDMI™ Technology with max. resolution up to 1920 x 1200 (1080P)
Supports Dual-link DVI with max. resolution up to 2560×1600 @60Hz
Supports D-Sub with max. resolution up to 2560×1440 @ 75Hz
Hybrid CrossFireX™ Support (For Windows Vista only)
Supports Microsoft® DirectX 10, OpenGL 2.0, Pixel Shader 4.0
Maximum shared memory of 512MB
Storage Southbridge
1 xUltraDMA 133/100
5 xSATA 3 Gb/s ports 1 x eSATA 3Gb/s ports with RAID 0, 1, 5 and 10 support
LAN Gigabit LAN
Audio Realtek® ALC1200 8
-Channel High Definition Audio CODEC
-Coaxial S/PDIF out port at back I/O
-DTS Surround Sensation UltraPC
12 USB 2.0 ports
ASUS Unique Features
ASUS Express Gate
ASUS Quiet Thermal Solution:
– ASUS AI Gear 2
– ASUS Q-Fan2
– 4+1 Phases ASUS Power Design
ASUS Crystal Sound
– ASUS Noise Filter
– ASUS Q-Shield
– ASUS Q-Connector
– ASUS O.C. Profile
– ASUS EZ Flash 2
Overclocking Features Intelligent overclocking
– AI Overclocking (Intelligent CPU Frequency Tuner)
– ASUS AI Booster Utility
Precision Tweaker 2
– vCore: Adjustable CPU voltage at 0.125V increment
– vChipset (N.B.): 25-step voltage control
– vDIMM: 35-step DRAM voltage control
SFS (Stepless Frequency Selection)
– FSB tuning from 200MHz up to 600MHz at 1MHz increment
– Memory tuning from 533MHz up to 1066MHz
– PCIe frequency tuning from 100MHz up to 200MHz at 1MHz increment
Overclocking Protection:
– ASUS C.P.R. (CPU Parameter Recall)
Special Features Uses 100% All High-quality
Conductive Polymer Capacitors!
ASUS MyLogo 2
AMD OverDrive Support*
* Advanced cooling system is required when advanced overclock functions
of AMD OverDrive are enabled.

Back Panel I/O Ports


1 x PS/2 Keyboard/Mouse
1 x S/PDIF Out (Optical)
1 x HDMI
1 x DVI
1 x D-Sub
1 x External SATA
1 x IEEE 1394a
1 x RJ45 port
6 x USB 2.0/1.1
8-Channel Audio I/O
Internal I/O Connectors 3 x USB connector (6 ports)
1 x Floppy disk drive connector
1 x IDE connector
5 x SATA connectors
1 x CPU Fan connector
2 x Chassis Fan connectors
1 x Power Fan connector
Front panel audio connector
1 x IEEE 1394a connector
1 x S/PDIF Out Header
Chassis Intrusion connector
CD audio in
24-pin ATX Power connector
4-pin ATX 12V Power connector
System Panel
BIOS 8 Mb Flash ROM
DMI 2.0
WfM 2.0
ACPI 2.0a
ASUS EZ Flash 2
Accessories UltraDMA 133/100/66 cable
FDD cable
SATA cables
SATA power cables
User’s manual
3 in 1 Q-connector
Support Disc Drivers
Express Gate
ASUS Update
Anti-virus software (OEM version)
Form Factor ATX Form Factor
12 inch x 9.6 inch ( 30.5 cm x 24.5 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 ease of installation. Poorly placed power connectors can also disrupt
airflow and make the system more thermally challenging.


The M3A78-T has a pretty good layout without any obvious problems. All the
important connectors are out of the way at the edges of the board — power
connectors, IDE and SATA ports, though three of the five SATA ports are placed
parallel to the PCI slots. While the board has an onboard IGP, it is an ATX
board, with multiple PCI Express 16x slots for users who want to implement a
CrossFire configuration. Hybrid CrossFireX with a low-end ATI graphics card
working in tandem with the IGP is also supported.

Another look.

Three heatsinks help cool the board’s chipsets and VRMs. The southbridge cooler
is low-profile, but broken up into many fins to maximize surface area. The northbridge
cooler has very broad fins and its overal size is impressive, though not so
tall as to interfere with most third party CPU coolers. The VRM cooler’s
fins are taller than usual, making it easier to catch airflow from a typical tower

Back panel connectors.

The back panel is fully-loaded with S/PDIF, HDMI, DVI, VGA, eSATA, and FireWire
ports. The only connectivity feature the M3A78-T seems to lack is Wi-Fi.


Though the M3A78-T is in many ways a premium motherboard, but
the presence of an IGP may limit the amount of frequency/voltage tweaking
that can be done.

“Advanced” options with maximum values entered.


Notable Available BIOS Adjustments
CPU Frequency 200Mhz to 600Mhz in 1Mhz increments
PCI-E Frequency 100Mhz to 150Mhz in 1Mhz increments
Memory Frequency 400/533/667/800Mhz (may depend on CPU)
Memory Timings Extensive options
CPU Voltage 0.800V to 1.600V in 0.0125V increments
Memory Voltage 1.80V to 2.50V in 0.02V increments
Northbridge Voltage HT: 1.2V to 1.4V in 0.02V
Core/PCIe: 1.1V to 1.6V in 0.02V increments
Sorthbridge Voltage 1.20V, 1.25V, 1.30V, 1.35V
VGA Core Clock 150Mhz to 1500Mhz in 1Mhz increments
Video Memory Size 32MB, 64MB, 128MB, 256MB, 512MB
Sideport Clock Speed 533Mhz to 850Mhz in varying increments
Sideport Memory Voltage 1.60V, 1.70V, 1.80V

Somewhat surprisingly, the M3A78-T BIOS is one of the most liberal
we have seen for an AMD motherboard. Ample frequency and voltage options are
available including those precluding to the IGP and its Sideport memory.

“Hardware Monitor.”

The “Hardware Monitor” menu supplies basic monitoring
of the system temperatures, fan speeds, and voltages. The board’s Q-Fan fan
control system has three settings: Silent, Optimal, and Performance.


Test Setup:

Measurement and Analysis Tools

We determine the overall system power
consumption at various states (measured using a Seasonic Power Angel), and
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.

Cool’n’Quiet was enabled and the following Vista features/services are always disabled during
testing to prevent spikes in CPU/HDD usage that are typical of fresh Vista installations:

  • Microsoft Defender
  • Windows Sidebar
  • Indexing
  • Superfetch
  • Aero interface

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.


1920×1080 | 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 an OEM 80 Plus power supply, notebook
hard drive and Blu-ray drive. The CPU is a X2 4850e, a mid-level dual core 45W
processor. It is cooled by a stock AMD heatpipe cooler with PWM fan connected
to a variable DC fan controller (so the fan’s power draw does not come into

Test Results: Asus M3A78-T
Test State
X2 4850e @ 2.5Ghz, C&Q
X2 4850e @ 1.5Ghz/1.0V
Mean CPU Use
Peak CPU Use
System Power
Mean CPU Use
Peak CPU Use
System Power
Sleep (S3)
Rush Hour
Coral Reef
Flight Sim.
Drag Race
CPUBurn + ATITool

At stock settings, the test system drawed 44W from the wall at idle, 70-73W
during video playback, and 87W with full CPU load. When the IGP was stressed
with ATITool, total power consumption jumped by 16W — the highest increase
we have encountered with an onboard graphics subsystem. Whether it performs
well or not, it is more power hungry compared to other recent IGPs. The video
playback results were good — about on par with previous AMD IGPs.

When we underclocked the CPU to 1.5Ghz, the system failed to render our VC-1
clips properly. The Flight Simulator clip was plagued by audio clipping, and
the Drag Race clip exhibited audio distortions as well as framerate fluctuations.

Test Results: Comparisons @ 2.5Ghz, C&Q
Test State
M3A78 Pro
Mean CPU Use
System Power
Mean CPU Use
System Power
Mean CPU Use
System Power
Sleep (S3)
Rush Hour
Coral Reef
Flight Sim.
Drag Race
CPUBurn + ATITool

The M3A78-T
consistently runs about 5W higher than the 780G based M3A78
, except with both the IGP and the CPU at max load, when it jumps to 9W. This
may indicate that the HD3300 graphics subsystem has higher idle power consumption,
though it may also be the power requirements of the M3A78-T board”s
extensive feature-set.

The Gigabyte GA-MA74GM-S2,
the most energy efficient mainstream AMD motherboard we’ve encountered, draws
6-13W less power.


For 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 & PC Probe readings.

SpeedFan allows for a high degree of functionality with the M3A78-T.
After some experimenting we found that it more or less matches Asus’ PC Probe
readings, except for the +12V rail. In addition, the sensor that correlated
to CPU temperature was 6°C higher than in PC Probe. The sensor labelled
“MB” seemed to be tied to the southbridge temperature — when
we placed a fan over the southbridge this reading dropped by a few degrees,
then increased to its original value when the fan was removed.

Fan control can be enabled for 3 of the 4 fan headers on the board — fans
connected to the header labelled PWR_FAN will run at full speed.. Setting PWM
modes 1-3 in the Advanced menu from “SmartGuardian” to “Software
Controlled” enables three different sets of controls. Speed01 controls
the CPU fan header using PWM (its range was 200 to 2500 RPM when a Scythe 92mm
PWM fan was connected to it), Speed02 controls the CPU fan header using voltage,
and Speed03 controls both the CHA_FAN1 and CHA_FAN2 3-pin headers in unison
using voltage. Voltage control is complete, from allowing users to bring fans
to a complete stop if desired.


We tested the board’s Q-Fan feature by connecting the fan on the CPU cooler
to a variable DC fan controller set to a relatively low 5V and proceeded to
stress the processor using CPUBurn. The CPU and Chassis fan speeds were monitored
and graphed using SpeedFan.

Q-Fan Behavior
Trigger Temp.
Range of Increase
Min Fan Speed
Max Fan Speed

The “Silent” and “Optimal” settings are pretty much identical
except for the trigger temperature which is seperated by 10°C. Both fans
run at about 60% speed until the trigger temperature is reached. The fan speeds
then increase over the next 6°C until they max out. The “Performance”
setting is even more aggressive, with a very high minimum fan speed, low range
of increase and low trigger temperature. With the minimum fan speed already
at 90%, the “Performance” setting is almost the same as having Q-Fan


With effective third party heatsinks and low power
CPUs , overclocking, to an extent, can improve performance without
compromising the noise level of a silent PC. A simple overclocking investigation
was conducted with the CPU multiplier set to 5x and RAM at 533Mhz/2.10V. 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.

The maximum FSB overclock with our X2 4850e.

We found that the board could take a maximum CPU frequency of only 220Mhz and
could thus theoretically overclock a capable CPU up to 10% above stock. At 225Mhz
and above artifacts appeared in ATITool, and at 250Mhz and above, graphical
distortions presented throughout the boot-up process. The nature of the instabilities
indicate that the IGP is tolerant of only mild increases in CPU frequency. We
should note that further overclocking may be possible by applying greater voltage
to the northbridge or southbridge. Overclocking is not one of our main testing
criteria; we perform a only cursory out-of-the-box overclocking examination.


To test how well the chipset heatsinks performed, we overclocked the CPU frequency
to 220Mhz, and lowered CPU cooling fan’s voltage to 7V to reduce the amount
of top down airflow the board received. After 20 minutes of stressing the system
with CPUBurn, the northbridge heatsink reached 70°C according to an IR thermometer
— hot enough that one second of direct skin contact was too much to handle.
The southbridge cooler on the otherhand was only mildly warm, registering 50°C.
The heatsink cooling the power regulation circuitry was also quite cool at only
60°C. Compared to previous boards, these results are quite good.


To get a rough estimate of how well the HD3300 GPU plays games, we attempted
to run 3DMark05/06. Unfortunately, we were unable to get either program to run.
When 3Dmark was loaded, the GUI would not appear and mouse movement became choppy
before Vista reported the application was not responding. We tried three different
sets of Catalyst drivers to no avail.

Other sources on the web seem to indicate that HD3300 performs very well, better
than any previous IGP. Neoseeker
reported that the IGP managed to outpace the HD 3450 discrete graphics card
in some benchmarks, and AMDZone
found that HD3300 had a 30-40% advantage compared to HD3200. With the power
consumption numbers resulting from our own testing, we anticipated it would
be the most powerful onboard graphics subsystem ever, and these reports
seem to confirm our expectations.


The HDMI output on our Asus MK241H 24″ (1920×1200) LCD monitor.

Previously we had many problems testing HDMI on a BenQ 19″ LCD. The signal
would frequently be blurry, distorted, overscanned, or at the wrong resolution.
Now, we have a new Asus
1920×1200 monitor and the results are much more promising. The
video signal was perfect, indistinguishable from DVI, and the audio passed through
without any difficulties, though the monitor only supports stereo sound. The
chipset is supposed to support Dolby Digital 5.1 and DTS 5.1 configurations
as well.


The Asus M3A78-T features the universal video decoder found on previous AMD boards,
but the IGP has been revamped, making it the most powerful ever, at least incrementally. The
southbridge has also been improved — SB750 finally gives AMD users RAID-5
support out-of-the-box. In addition, it is fully loaded with almost every feature
one may desire: eSATA, FireWire, S/PDIF, HDMI, CrossFire, etc. The board is
also well-cooled — Asus placed a very large heatsink on the northbridge and
more importantly, one to cool the VRMs. VRM overheating was something of an
issue on previous AMD boards that prevented the use of high TDP CPUs on some
models — with the M3A78-T, this is something you won’t have to worry about.
And finally as silent PC fanatics, we appreciate the ability to control three
fans without requiring to dish out for a fan controller.

The IGP is undoubtedly superior to anything else out there — the level
of performance more or less matches low-end discrete cards. Keep in mind though
that it is still not great for playing modern games at higher resolutions.
HD 3300 is no substitute for a good discrete graphics card for 3D gaming. Luckily, the M3A78-T gives
you many graphics options. You can use the IGP on its own,
Hybrid CrossFireX, a single discrete card, or two discrete cards in CrossFire
— the choice is entirely yours. If you do decide to onboard graphics is
enough for you, keep in mind the higher power draw compared to the 690G, 740G,
and 780G chipsets.

Overall the M3A78-T is an excellent motherboard. While we have talked a lot
about the IGP, ultimately, whether the M3A78-T is a good buy will depend on
how many of its other features will be used on a regular basis. It offers a
lot more functionality than your typical budget board, and it comes at a price.


* Fastest IGP ever
* Versatile feature set
* Well cooled
* Good HD video playback
* 3 fans can be controlled


* High power consumption
* Pricey

Our thanks to ASUSTeK
for the Asus M3A78-T sample.

* * *

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

M3A78 Pro: An ATX 780G Motherboard

M3N78 Pro: Geforce 8300 & HybridPower Explored

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