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Asus P5E3 Premium: A Mean, Green Motherboard?

Asus P5E3 Premium: A Mean, Green Motherboard?

August 17, 2008 by Lawrence Lee

Product Asus P5E3 Premium/WiFi-AP

Intel LGA775 motherboard
Manufacturer ASUSTeK
Street Price US$360~430

The Asus P5E3 Premium is Asus' flagship Intel motherboard and sells for around $400, which is enough to buy a whole computer system these days, albeit an economy model. Despite the ultra-high cost, PC gamers and enthusiasts
drool over such products. Asus has thrown everything they have up their sleeves in making the P5E3 Premium the
ultimate motherboard. The board is powered by Intel's X48 chipset, featuring
PCI-E 2.0, CrossfireX capability and ultra-fast DDR3 memory support. It also
has plenty of practical features including FireWire, gigabit ethernet, high
definition audio, wireless draft-N, and versatile RAID options. In this
board's endless feature list is something
Asus calls EPU.

The P5E3 Premium ships in a sleak black box with a plastic handle.

EPU (aka Energy Processing Unit) is a built in IC controller that Asus claims
can create up to 80.23% in CPU power savings. It accomplishes this by adjusting
the CPU's power phases from 8 to 4 during low load, allowing for higher VRM
efficiency. This chip was the center of a controversy between Asus and Gigabyte
earlier this year after Gigabyte not only claimed their DES (Dynamic Energy Saver) technology
was superior, but also made some disparaging remarks regarding Asus' claims.
DES, as the name suggests, is more dynamic in nature, adjusting the power phases
variably rather than just having two states. After several back-and-forths and
the threat of a lawsuit, Gigabyte issued
an apology in July
, though still insisting DES is the better technology.

8-phase power is lowered to 4-phase during light load by the EPU chip,
resulting in greater VRM efficiency.

Asus P5E3 Premium/WiFi-AP Specifications (from
product web page
Intel Socket 775 Core™2 Quad/Core™2
Extreme/Core™2 Duo/Pentium® Extreme/Pentium® D/Pentium®
4 Processors

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

Support Intel® next generation 45nm CPU
Chipset X48

Intel ICH9R

Intel Fast Memory Access Technology
Front Side Bus
1600/1333/1066/800 MHz
Memory 4 x DIMM, 8 GB, DDR3 1800*/2000*/1600/1333/1066/800
Non-ECC,Un-buffered Memory

Dual Channel memory architecture

Supports Intel® Extreme Memory Profile (XMP)

* Overclocking speed

** For the X.M.P. support, CPUs with FSB 1333 or above are recommended.

*** Refer to or this user manual for the Memory QVL (Qualified
Vendors List).
Expansion Slots 3 x PCIe x16 (blue @PCIe2.0 x16 mode,
black @PCIe x4 or x1 mode) supports CrossFire Technology

1 x PCIe x1

2 x PCI
Storage Southbridge

6 xSATA 3 Gb/s ports Support RAID 0,1,5,10 Intel Matrix Storage Technology

JMicron® JMB363 PATA and SATA controller

External SATA 3.0 Gb/s port (SATA On-the-Go)

2 x 1 xUltraDMA 133/100/66 for up to 2 PATA devices

Support RAID 0,1,JBOD
Dual Gigabit LAN controllersMarvell
88E8056® PCIe Gigabit LAN controller featuring AI NET2

Realtek RTL8110SC® PCI Gigabit LAN controller featuring AI NET2
Wireless LAN

- 300Mbps* IEEE 802.11n (Draft) and backwards compatible with IEEE 802.11g
/ b

- Software Access Point mode

*300Mbps is IEEE 802.11n draft specification. Actual throughput will vary
depending on the wireless environment and other parameters
ADI® AD1988B 8 -Channel High Definition

AI Audio 2

Coaxial / Optical S/PDIF out ports at back I/O

Support Jack-Sensing, Enumeration, Multi-streaming
IEEE 1394
2 Agere® L-FW3227 1394a controller
supports x 1394a ports (one at midboard; one at back panel)
10 USB 2.0 ports (4 ports at mid-board,
6 ports at back panel)
ASUS AI Lifestyle ASUS Quiet Thermal Solution

- ASUS Fanless Design: Pure Copper Heat-pipe solution

- ASUS Fanless Design: Stack Cool 2

- ASUS Q-Fan 2

- ASUS Optional Fan for Water-cooling or Passive-Cooling only ASUS Power
Saving Solution

- ASUS EPU (Energy Processing Unit)

- ASUS 3rd Generation 8-phase Power


ASUS AI Lifestyle

- ASUS AI Direct Link

- ASUS Express Gate

- ASUS WiFi-AP @n

ASUS Crystal Sound

- ASUS Noise Filter

- ASUS AI Audio 2


- ASUS Q-Connector

- ASUS Q-Shield

- ASUS O.C. Profile

- ASUS CrashFree BIOS 3

- ASUS EZ Flash 2

- ASUS AI Slot Detector
Overclocking Features
Intelligent overclocking tools

- ASUS AI Booster Utility

Precision Tweaker

- vChipset (N.B.): 49-step voltage control

- vDIMM: 25-step DRAM voltage control 65 -step DRAM voltage control

- vCore: Adjustable CPU voltage at 0.0125V increment 0.00625V - vFSB Termination:
16-step reference voltage control

- vCPU PLL: 65-step CPU PLL voltage control

SFS (Stepless Frequency Selection)

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

Memory tuning from 800MHz up to 3200MHz

- PCI Express frequency tuning from 100MHz 150MHz at 1MHz

Overclocking Protection

- ASUS C.P.R.(CPU Parameter Recall)
Special Features
Multi-language BIOS

ASUS MyLogo 3
Back Panel I/O Ports
1 x PS/2 Keyboard

2 x External SATA

1 x S/PDIF Out

1 x IEEE 1394a

2 x RJ45 port

6 x USB 2.0/1.1

8 Channel Audio I/O

2 x WiFi-AP @n antenna jack
Internal I/O Connectors
2 x USB connectors support additional
4 USB ports

1 x Floppy disk drive connector

1 x IDE connector

6 x SATA connectors

1 x IEEE 1394a connector

1 x CPU Fan connector

1 x Chassis Fan connector

1 x Power Fan connector

1 x COM connector

1 x S/PDIF Out connector

2 x4-pin ATX 12V Power connector

Power connector

24 Front panel audio connector

Chassis Intrusion connector

CD/AUX audio in

System Panel
16 Mb Flash ROM

Award BIOS


DMI 2.0

WfM 2.0


ACPI 2.0a

Multi-language BIOS

ASUS EZ Flash 2

ASUS CrashFree BIOS 3
PXE WfM 2.0,DMI 2.0,WOL by PME,WOR
by PME
UltraDMA 133/100/66 cable

FDD cable

6 x Serial ATA cables

1 x 2-port Serial ATA power cable

ASUS Q-Shield

User's manual

ASUS WiFi-AP @n manual

3 in 1 Q-connector

1 x 2-port USB2.0 / 1-port IEEE1394 module

2 x Optional Fan for Water-Cooling or Passive-Cooling only

ASUS WiFi-AP @n omni-directional antenna
Support CD
ASUS WiFi-AP @n Wizard




Anti-virus software (OEM version)

ASUS Update

Image-Editing Suite
Form Factor

ATX Form Factor

12 inch x 9.6 inch (30.5 cm x 24.4 cm)


Along with the typical accessories, the P5E3 Premium also comes with two optional
blower fans that can be attached the VRM heatsinks, two WiFi antennas with magnetic
bases, and extra FireWire/USB ports in the form of a PCI cable bracket.

The bundle.

A lot of thought has been put into connector placement. SATA, IDE and Floppy
ports are all on the edge of the board, along with the 24-pin ATX power connector.
Fan headers litter the board — there are six all together, all on the outer


It is of course, not perfect. The 8-pin EPS12V connector near the top would
be difficult to access in a typical ATX tower, especially due to its close proximity
to the VRM heatsinks. A large CPU cooler such as the Scythe Ninja would make
it even less accessible. In addition, the last PCI-E slot, the one that would
be used for a third video card in a triple Crossfire setup should be higher
on the board, to allow for a dual-slot card.

Back panel.

The back panel is jam-packed with every port one could imagine. It has dual
gigabit ethernet and wireless-N, analog and S/PDIF audio (both coaxial and optical),
FireWire, and eSATA. The PS/2 mouse port has been done away with — this
will be a problem if you wish to use an older KVM with the board.

Another angle.

The IDE port and 4 of the 6 SATA connectors are on their sides, making cable
management a snap. The heatsink array is short enough to allow most properly-designed
third party heatsinks to be installed without issue. The tallest point is on
the northbridge, approximately 34 mm high.

A closer look at the heatsinks.

The heatsinks are a clear demonstration of the extravagance of the P5E3 Premium.
Along with the northbridge and southbridge, three sets of VRMs are covered with
copper heatsinks, all connected via heatpipes. In thoery, as the heatpipe fluid
heats up, it should travel toward wherever the temperature is lower, resulting
in a balance between all the chips being cooled. Assuming they all have the
same heat tolerance, it's a good system.


A quick look at the underside of the board reveals backplates for both the
northbridge and southbridge heatsinks, for extra security. They are held down
by screws unlike the VRM heatsinks, which use simple push-pins.


The BIOS is extremely liberal, as one can expect for an enthusiast
board. Instead of presenting screenshot after screenshot of the AI Tweaker
menu, we've summed up the most important options in the table below:

Notable Available BIOS Adjustments
CPU/FSB Frequency 200Mhz to 800Mhz in 1Mhz increments
PCI-E Frequency 100Mhz to 180Mhz in 1Mhz increments
CPU Voltage 0.85000V to 2.10000V in 0.00625V increments
DRAM Voltage 1.50V to 2.78V in 0.02V increments
Northbridge Voltage 1.25V to 2.21V in 0.02V increments
Southbridge Voltage 1.05V to 1.20V in 0.15V increments

Hardware Monitor.

The Hardware Monitor can report the fan speed of up to 5 fans.
The CPU fan on its own, and the Chassis fans (connected to the 4 CHA_FAN headers)
as a group can be controlled with various settings. The options are"Full
Speed," "Profile," and "Manual."

In Profile mode, you may select one of three automatic settings:
"Optimal," "Silent," and "Performance." In Manual
mode, you may select a "Fan Start-Up Ratio" of between 1-99%, a
"Target Temperature" of 1-99°C, and a "Temperature Tolerance"
of 1-7°C. For the Chassis fans, the Profile mode is replaced with a more
simplified Fixed mode, allowing one to run the 4 fans at a single set speed
between 1-99%.

Express Gate

Express Gate is Asus' re-branding of SplashTop, an instant-on
Linux desktop from a company called DeviceVM. It can be accessed as quickly
as the system takes to get to the POST screen. It is enabled by default in
the BIOS, and thus appears on first bootup, giving you access to the internet
via ethernet or WiFi.

Express Gate — instant internet access.

This is very useful if you just turned on the system to shoot
off a quick e-mail or instant message, or perform some other trivial online
task. In less than 10 seconds you can be watching a video on YouTube or placing
a Skype call. In addition there is the possibility of even more functionality,
as Express Gate can be upgraded once newer versions are made available by

YouTube anyone?

If the majority of your PC time is spent on the internet, you
should feel right at home with Express Gate. You can get a lot done on the
web — programs that live strictly online are becoming rapidly popular. Some
believe that the internet is the next great operating system — that as long
as you can get online, the choice between Windows, Mac OS X and Linux will
be moot. Either way, Express Gate is still the fastest way we know of to watch
someone get hit in the groin with a baseball or the Muppets singing "Never
Gonna Give You Up."


Test Setup:

Measurement and Analysis Tools

Test setup.

The components chosen for testing where selected to reflect
a typical, high-end gaming set-up. Except for the CPU and heatsink, they were
the highest performing parts we had on hand. The E7200 processor was not our
first choice, but unfortunately it was the first CPU we tested on the board
that actually worked properly. A QX9650 and E6750 were tried as well, but
for some odd reason, the board automatically overclocked both processors to
450Mhz FSB and increased the CPU voltage, resulting in SpeedStep being disabled
and preventing us from testing the EPU feature, which does not function in
an overclocked state. We attempted to get around it by setting the CPU speed
manually and updated the BIOS, but neither workaround resulted in any kind
of resolution.


EasyTune overclocking.

The EPU feature requires a driver as well as the installation of Asus'
AI Gear3+ application. There are five different modes to choose from: Max.
Power Saving, Medium Power Saving, High Performance, Turbo, and Auto. Each
setting is represented visually by different modes of transport, with the
man walking being the slowest and the rocket being the fastest. There is
also an Automatic mode (the wand) that scans the system to determine the
most optimal overclocking settings. When we tried it, it concluded that
the same settings as Medium were appropriate. For testing, we tried each
mode and measured the system power consumption at idle, during playback
fo a VC-1 clip, and during load.

EPU Setting
CPU Manipulation
System Power (AC)
Clock Speed
CPU Voltage
Max. Power Saving
Med. Power Saving


High Performance


Turbo Performance


CPU voltage reported by CPU-Z.

How well EPU performs unfortunately is fogged by the fact that the CPU
clock speed and voltage are also altered. Whether the manipulation of the
CPU's power phases or simple underclocking and undervolting are resulting
in energy savings is hard to tell. Both the idle and load CPU voltage are
changed at each level, effectively altering SpeedStep to suit the clock
speed EPU has set. The changes are rather moderate, with a slight underclock
in effect when using the Medium mode and small overclock using Turbo. Max.
Power Saving is the most drastic, severely underclocked the CPU to 1.44Ghz
(more than 40%) regardless of CPU load. It's fairly easy to reap significant
power savings when performance is crippled.

System Power Consumption (AC)
EPU - High Performance
EPU Disabled - Stock EIST
CPU speed: 1.60Ghz idle, 2.53Ghz load

CPU voltage: 1.128V idle, 1.176V load

So is EPU actually doing anything? After we uninstalled the EPU driver
and AI Gear and rebooted the system, a quick check with CPU-Z confirmed
that the stock settings with EIST enabled were identical to the High Performance
EPU profile. A comparison of the power consumption between the two states
showed very little difference. Our power analyzer rounds off to the nearest
tenth of a watt — if it didn't we might not have any results at all. The
power savings were so minimal that they're hardly worth mentioning. It's
quite possible that EPU just didn't work properly on our test sample, as
it did give us trouble early on when we were selecting a CPU to use with
it. Another possibility is the E7200 processor we ended up using is not
power hungry enough for EPU to make any real difference.


The extent to which fans can be controlled, and how they behave when left
on automatic control is a major criteria for us when it comes to motherboards.
For $370, we expect good things. The P5E3 Premium is blessed with six fan headers,
most of which are towards the front of the board.

Fan header layout.

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 vs. PC Probe.

As a monitoring program, it is a little less desirable, commonly reporting
extra erroneous temperatures and as well as frequently misreading voltages,
as in evident in the screenshot above. It does however get the main readings
right, reporting 5 fan speeds and getting the CPU and system temperature correct,
or at least the same readings as Asus' PC Probe. The fan header labels are incorrect
however. To avoid confusion, relabel them to match the table below:

SpeedFan: Fan Header Correlations
Sys Fan
CPU0 Fan
Aux0 Fan
CPU1 Fan
Aux1 Fan

SpeedFan: Fan Speed Controls
CHA_FAN 1-4, Very Limited
CPU_FAN, Full Control (PWM only)

To control the CPU fan header, go into the Advanced menu and find PWM#2. Change
its mode from "SmartFanIII" to "Manual PWM Control." Using
the Speed02 drop-box, we were able to adjust a Xigmatek PWM fan speed to between
930 and 2520 RPM (3-pin fans run at full speed). We were also able to control
all the Chassis Fans with the Speed01 drop-box, but it was very limited —
1400 RPM at 0% and 1500 RPM at 100% using a Scythe Kama Flow 80mm fan.

BIOS Fan Profiles

To test the the different fan profiles available in the BIOS, we first hooked
up the Zerotherm CPU fan to a custom DC fan controller and attached a Xigmatek
PWM fan to the CPU fan header instead, placing it away from the test system
so it would not affect the temperature. Prime95 was then run to heat up the
CPU. We set the Zerotherm fan to 5V to ensure the CPU would heat up more than
usual. Finally, we tracked the CPU temperature as well as the fan speed of the
Xigmatek fan.

CPU Fan Speed (RPM)
CPU Temp.
Fan Profile

The automatic fan profiles are typical of what we've seen in the past from
Asus. The changes in fan speed are rather abrupt, increasing in a varying number
of steps (depending on the profile selected). The fan speed begins to pick up
at approximately 55°C, 50°C and 45°C for the Silent, Optimal, and
Performance profiles respectively. Though the Performance profile does increase
the fan speed the most, it is far from aggressive as the Xigmatek fan is capable
of spinning at more than 2000 RPM.

CPU Fan Speed (RPM)

Manual Profile Settings
Start-Up Ratio: 60%

Target Temp: 40°C

Tolerance: 2°C
Start-Up Ratio: 40%

Target Temp: 50°C

Tolerance: 2°C

The Manual profile settings gave us mixed results. The Fan Start-Up Ratios
seemed to be accurate — at 60% the fan speed started at 1200 RPM, and at 40%,
950 RPM. The Target Temperature was spot on when set to 50°C, but when set
to 40°C, the fan did not increase in speed until the CPU temperature reached
48°C. It's probably better to use one of the automatic fan profiles instead.
The Chassis fans, as a group, can also be set to Manual (with the Target Temperature
being System temperature rather than CPU) as well as Full Speed and Fixed Speed.


As with most boards based on Intel chipsets, the P5E3 Premium turned out to
be a fantastic overclocker — it POSTed consistantly with the FSB set to 560Mhz
(multiplier dropped to 6). This means in theory, Yorkfield and Wolfdale processors,
if capable of such speeds, can be overclocked to 68% over stock.


The built-in draft-N wireless adapter gave us little trouble, and detected
and connected to our wireless network without difficulty via Wireless Zero Configuration.
The provided Asus configuration utility however was problematic — it claimed
the adapter was disconnected, which obviously wasn't true. The range was good,
as far as we could tell — moving throughout the building carrying a running
system and monitor to check the signal was impractical. There were no drop-outs
during testing.


Though the board shipped with two optional fans that can be fit on any of the
VRM heatsinks, we found the entire heatpipe array performed adequately without
any active cooling. During heavy load, we measured the temperature of each heatsink
and found those cooling the VRMs were actually the coolest. When meausred with
a laser thermometer, they registered less than 45°C, while the southbridge
and northbridge came close to 55°C and 70°C respectively. The heatpipes
closest to the chipsets were consistantly warmer than the others. The optional
fans are fairly loud by our standards, with poor undertones. They sounded very
buzzy with a slightly high-pitch whine, as one can expect from small blower
fans. We wouldn't bother with them.

Optional fan installed.


The Asus P5E3 Premium is bursting with features: FireWire, gigabit ethernet, wireless-N, eSATA, ATI Crossfire
— the list goes on and on. Though the CPU support on our sample was problematic,
this was probably isolated to our sample. Other reviews around the web do
not mention anything like the CPU / EPU problems we encountered. The board's
main negative is obviously the price. Many users would balk at a $200 motherboard,
and the retail price is almost double that. To make matters worse, the board
lacks DDR2 support, and DDR3 memory is quite expensive at this time.

Is it suitable for a silent PC? With the board's passive cooling being sufficient,
the only true measures we can use are power consumption and fan control. Power
consumption is difficult to gauge without comparable products to test it against,
and we weren't able to get conclusive results with EPU. If the trouble we had
with CPU selection is any indicator, we may simply have a bad sample on our
hands. However, if EPU saved 10W or even 20W, going with a different chipset
and/or feature-set could be just as beneficial. In addition, it's a feature
that is somewhat misplaced on this board. With a high-end chipset and triple
Crossfire capability, it's a likely choice for gung-ho gamers and enthusiasts
looking to squeeze out the most performance they can out of their hardware —
not to save power. Fortunately, EPU is also available on Asus' P5Q line (using
the more mainstream P45 chipset) and it will probably appear on future motherboards
as well. Hopefully EPU will simply become standard and you won't have to pay
extra for it.

The fan control is very good, though still not ideal. The CPU fan can be controlled
manually using SpeedFan, or with the various automatic profiles in the BIOS.
The Chassis fans are another matter. They cannot be really controlled via the
desktop, and in the BIOS, the only automatic control is via a manual profile
— which doesn't always behave properly. However, you can still set all
4 of them to a fixed speed and that's a lot more than most boards are capable

One of the most positive things about the P5E3 Premium is
Express Gate. The fast boot-up time coupled with its ease of use makes it incredibly
convenien. It's also a somewhat subversive promotion of Linux, although not a direct shot at Microsoft like the orignal Linux-based Asus EEE PC sub-notebook.
Many PC users could probably live with just Express Gate alone. It lacks basic productivity applications, a video
player and DVD/hard disk access — if these were added, Express Gate would truly turn
some heads.


* Amazing feature-set

* Can control 5 fans

* Express Gate

* Overclocks well

* Ridiculous price

* CPU support buggy

* EPU a bust?

Our thanks to Asus for the P5E3 Premium motherboard sample.

* * *

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