Asus Radeon HD 4870 Matrix

The Asus Radeon HD 4870 Matrix features two fans without a restrictive shroud, giving the heatsink more room to “breathe”, and providing direct airflow to the GPU and board components. By sharing the cooling work between two fans, it should be a quieter, cooler card. We pit the Asus Matrix against ATI’s reference design.

March 8, 2009 by Lawrence Lee

Asus EAH4870

PCI-E Graphics Card
Street Price

For most high powered cards, the conventional cooler consists of a copper base-plate
connected to a mass of aluminum fins via heatpipes. While this is an effective
way to draw heat away from a hot GPU, the method employed to get rid of all
this heat is what typically makes these cards noisy — a loud blower fan
with a plastic housing covering the entire unit to ensure air is forced out
the back of the case rather than being scattered around the interior. It takes
a significant amount of airflow to make this model work, especially when the
GPUs in question pull more than 100W worth of power.

Asus HD 4870 Matrix next to a reference HD 4870
1GB sample from ATI. Both cards measure 24.1 cm, but Matrix weighs
only 550g compared to ATI’s 800g.


Asus’ Radeon HD 4870 Matrix.

The Asus Radeon HD 4870 Matrix takes a different approach, utilizing
two downward-blowing fans without the restrictive shroud. This gives the heatsink
more room to “breathe” and provides the GPU and board components with
direct airflow. It also potentially cuts the amount of work each individual
fan has to do. By all accounts, it should be a quieter, cooler card. The Radeon
HD 4870 GPU is rated at 125W TDP according to ATI — a prime candidate for an improved cooling

ATI Radeon HD 4870 1GB specifications according to GPU-Z.
The HD 4870’s reference speeds are 750MHz / 900MHz.


Asus HD 4870 Matrix specifications.
GPU and memory clocks are 20MHz higher.


Asus EAH4870 MATRIX: Specifications
(from the
product web page

Our sample came as a bare card without a box or accessories. According to the
specification sheet, the retail version ships with a component-out cable, DVI
to VGA adapter, and DVI to HDMI adapter.


The card’s main attraction is its dual fan cooler, which bears a resemblance
to the one used on the EN9800GT
, albeit with a less confined design.

While the cooler design is more open than the stock HD 4870 heatsink,
there is still plenty of plastic designed to direct airflow out the back.
With the fans blowing straight down onto the PCB, there seems little reason
to do this.


On the trace side of the card, only 7 screws are visible. 4 secure the
heatsink while remaining 3 support a plastic guard on the PCB’s top edge.


The card’s main 73mm wide fan sits atop the GPU and the auxiliary 64mm
fan blows directly over the VRM circuitry. The HD 4870 requires two six-pin
PCI-E power connectors.


The cooler is essentially a dual radial cooler design, but one heatpipe
is connected to a narrow block of fins at the back, sitting next to a


Installed in our test-bed


Warning — removing the heatsink from a card generally voids the product’s
warranty. Do so at your own risk. Note that all testing on the card was performed
before the cooler was removed.

The reference ATI RAdeon 4870 heatsink is composed of a massive copper block connected to
two heatpipes.


The Asus Matrix heatsink features a series of heatpipes snaking around the
two fans and into a block of fins at the rear. The card’s memory and VRM
chips are all bare — with two fans positioned over them, no extra heatsinks
are required.


The fans are manufactured by Yen Sun Technology.

Asus’ iTracker Application

The most exciting and innovative feature of this Matrix card is the
functionality provided by Asus’ iTracker application. It allows the user to
change GPU and memory clock speeds, voltages, and fan control settings.

iTracker Default profile page.

iTracker comes with four preset modes — Optimized, Gaming, Default, and
Power Saving, with both 2D and 3D settings available. Surprisingly frequency
and voltage manipulation hasn’t been crippled as the GPU clock has a range of
250 MHz to 950 MHz and memory can be adjusted from 900 MHz to 2200 MHz. GPU
and memory voltages can be tweaked from 1.000V to 1.6000V and 1.300V to 1.800V
respectively. We recommend only making minor adjustments and testing for stability
after each change. Caution should be used when this amount of control is allowed.

iTracker Modes: Clock Speeds & Voltages
GPU Voltage
Memory Voltage
Optimized 2D
500 MHz
950 MHz
Optimized 3D
800 MHz
950 MHz
Gaming 2D
770 MHz
950 MHz
Gaming 3D
800 MHz
950 MHz
Default 2D
770 MHz
920 MHz
Default 3D
770 MHz
920 MHz
Power Saving 2D
500 MHz
500 MHz
Power Saving 3D
770 MHz
500 MHz

Incidentally, the Power Saving mode actually lowers the memory clock lower
than iTracker allows if you do it manually. Also, undervolting
the GPU below 1.230V and the memory below 1.440V caused artifacts to appear
occasionally on the screen, even when we set the clocks to the lowest possible.
For testing we used the Power Saving mode, but altered the 3D settings so they
matched those of the Optimized and Gaming modes. During video playback the clock
speeds locked to the default 770 / 920 MHz regardless of the profile used.

While the card has two fans, iTracker can only change how fast the smaller,
auxiliary fan (the one over the VRM section of the board) spins. Unfortunately,
the fan does not spin up below 40% speed, so the fan starts at a very high minimum
speed of 3000 RPM. This means it can only be turned completely off or made to
spin faster.

iTracker Information page.

iTracker is also an excellent for monitoring. It displays the video card’s
clock speeds, voltages, temperatures and fan speeds. It, along with power consumption
measurements confirmed that both voltage controls were actually functioning
and not just for show.


Our test procedure is an in-system test, designed to:

1. Determine whether the card’s cooler is adequate for use in a low-noise system.
By adequately cooled, we mean cooled well enough that no misbehavior
related to thermal overload is exhibited. Thermal misbehavior in a graphics
card can show up in a variety of ways, including:

  • Sudden system shutdown, blue-screen or reboot without warning.
  • Jaggies and other visual artifacts on the screen.
  • Motion slowing and/or screen freezing.

Any of these misbehaviors are annoying at best and dangerous at worst —
dangerous to the health and life span of the graphics card, and sometimes to
the system OS.

2. Estimate the card’s power consumption. This is a good indicator of how efficient
the card is and will have an effect on how hot the stock cooler becomes due
to power lost in the form of heat. The lower the better.

3. Determine the card’s ability to play back high definition video, to see
if whether it is a suitable choice for a home theater PC.

Test Platform

Measurement and Analysis Tools

  • CPUBurn
    processor stress software.
  • ATITool
    artifact scanner to stress the GPU.
  • FurMark
    stability test to stress the GPU.
  • GPU-Z to
    monitor GPU temperatures and fan speed.
  • SpeedFan
    to monitor CPU temperature.
  • Seasonic
    Power Angel
    AC power meter, used to measure the power consumption
    of the system
  • A custom-built variable fan speed controller to power the system
  • PC-based spectrum analyzer
    — SpectraPlus
    with ACO Pacific mic and M-Audio digital
    audio interfaces.
  • Anechoic chamber
    with ambient level of 11 dBA or lower

Testing Procedures

Our first test involves recording the system power consumption using a Seasonic
Power Angel as well as CPU and GPU temperatures using SpeedFan and GPU-Z during
different states: Idle, under load with CPUBurn running to stress the processor,
and with CPUBurn and ATITool’s artifact scanner (or FurMark — whichever produces
higher power consumption) running to stress both the CPU and GPU simultaneously.
This last state mimics the stress on the CPU and GPU produced by a modern video
game. The software is left running until the GPU temperature remains stable
for at least 10 minutes. If artifacts are detected by ATITool or any other instability
is noted, the heatsink is deemed inadequate to cool the video card in our test

If the heatsink has a fan, the load state tests are repeated at various fan
speeds while the system case fan is left at its lowest setting of 7V. If the
card utilizes a passive cooler, the system fan is varied instead to study the
effect of system airflow on the heatsink’s performance. System noise measurements
are made at each fan speed.

Estimating DC Power

The following power efficiency figures were obtained for the
Seasonic S12-600
used in our test system:

Seasonic S12-500 / 600 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.



BASELINE, with Integrated Graphics: First, here are the results of
our baseline results of the system with just its integrated graphics, without
a discrete video card. We’ll also need the power consumption reading during
CPUBurn to estimate the actual power draw of discrete card later.

VGA Test Bed: Baseline Results
(no discrete graphics card installed)
System Power
DC (Est.)
Ambient temperature: 21°C
Ambient noise level: 11 dBA
System noise level: 12 dBA

ATI Radeon HD 4870 1GB:

VGA Test Bed: ATI Radeon HD 4870 1GB
System State
Fan Speed
Mem. Temp
Shader Temp
System Power
DC (Est.)
990 RPM
13 dBA
CPUBurn + ATITool
1750 RPM
20 dBA
CPUBurn + FurMark
1750 RPM
20 dBA
Ambient temperature: 21°C.
Temperatures recorded via GPU-Z.

The ATI reference card cooler was surprisingly quiet when idle, just barely
increased the noise above the system’s ambient level. Up close, the clicking
of the blower fan is audible, but shielded by a little distance, a side panel
and some foam, only a gentle hum was barely audible. When placed under load,
the fan speed almost doubled and the noise level increased to 20 dBA, sounding
like a small hair dryer, albeit smoother than most blower fans and unvarying
in pitch/tone. Honestly, it’s not too bad, especially for a stock cooler.

The temperatures were a touch high, but nothing to be concerned about, especially
at the noise levels measured. The GPU heated up from 76°C idle to 85°C
on full load. The memory and shader temperatures increased by a similar amount.
We feel it’s just the right balance of noise and cooling performance.

Asus Radeon HD 4870 512MB Matrix:

Our test results were rather unusual due to the nature of the card’s fan control.
Idle, both fans were inactive to begin with, but once it heated up to a certain
point (varied depending on what iTracker mode was used), the main fan kicked
in at what we assume was its minimum speed: 2800 RPM. It remained operating
at this speed for a few minutes until the GPU cooled down sufficiently and then
promptly shut it self off. Given the way fan control was implemented, the card
was never quiet for more than a few minutes at a time.

VGA Test Bed: Asus Radeon HD 4870 512MB Matrix
System State
Fan 1 Speed
Fan 2 Speed
Mem. Temp
Power Temp
System Power
DC (Est.)
0 / 2800 RPM
12 dBA / 20 dBA
54 – 70°C
60 – 67°C
53 – 55°C
123 – 128W
97 – 101W
55 – 70°C
60 – 67°C
54 – 55°C
198 – 202W
161 – 165W
CPUBurn + ATITool
3300 RPM
3100 RPM
27 dBA
CPUBurn + FurMark
3300 RPM
3160 RPM
27 dBA
Ambient temperature: 21°C.
Temperatures recorded via iTracker.

With the main fan cycling on and off, the GPU temperature had a range of around
15°C. Power consumption readings varied depending on how hot the card was
and whether the main fan was on or off. The system noise level was 20 dBA when
the fan was active. The fan had poor undertones — up close it sounded rickety
like something was obstructing it. Simply loading GPU-Z also caused the fan
to inexplicably turn on, so we used the iTracker utility to measure the various
GPU temperatures.

The auxiliary fan was very similar — it had the same poor acoustic character
and high starting speed. When set to the “Auto” in iTracker, it turned
on almost immediately after 3D stress testing with ATITool or FurMark began
and ran at its minimum speed, resulting in a significant increase in noise level
to 27 dBA. The temperatures, while a fair improvement over ATI’s reference card,
came at a heavy auditory cost. As we used an overclocked setting, it was unsurprising
that the card pulled about 10W AC more than ATI’s card when placed under a full


The power consumption of an add-on video card can be estimated by comparing
the total system power draw with and without the card installed. Our results
were derived thus:

1. Power consumption of the graphics card at idle – When CPUBurn is
run on a system, the video card is not stressed at all, and stays in idle mode.
This is true whether the video card is integrated or an add-on PCIe 16X device.
Hence, when the power consumption of the base system under CPUBurn is subtracted
from the power consumption of the same test with the graphics card installed,
we obtain the increase in idle power of the add-on card over the
integrated graphics chip (Intel GMA950). (The actual idle power
of the add-on card cannot be derived, because the integrated graphics does draw
some power — we’d guess no more than a watt or two.)

2. Power consumption of the graphics card under load – The power draw
of the system is measured with the add-on video card, with CPUBurn and FurMark
running simultaneously. Then the power of the baseline system (with integrated
graphics) running just CPUBurn is subtracted. The difference is the load power
of the add-on card. (If you want to nitpick, the 1~2W power of the integrated
graphics at idle should be added to this number.) Any load on the CPU from FurMark
should not skew the results, since the CPU was running at full load in both

Both results are scaled by the efficiency of the power supply (tested
) to obtain a final estimate of the DC power consumption.

Power Consumption Comparison (DC)
Est. Power (Idle)
Est. Power (ATITool)
Est. Power (FurMark)
ATI HD 4830*
Diamond HD 4850
Asus ENGTX260
ATI HD 4870 1GB
Asus HD 4870 512MB Matrix**
* sample with unknown number of stream processors
** average idle power used

Even though ATI’s card had an extra 512MB to power, the overclocked Asus Matrix drew an extra 6-7W DC on a full load. On the bright side, idle power
was actually lower by almost 20W — the Power Saving mode
during 2D use pays off.


The Matrix card had a nifty utility to display the card’s operating
voltages and frequencies. The ATI card had no such application, so to get a
better idea of its inner workings we took a look at the board’s BIOS. We used
GPU-Z to extract the card’s BIOS and Radeon
BIOS Editor
to examine how the card’s clock speeds and voltages were set
to behave.

ATI HD 4870 1GB: BIOS Clock/voltage settings.

Displayed in green, yellow and red are the card’s settings for idle, UVD, and
3D. We confirmed the frequency changes with GPU-Z, but the BIOS shows us a voltage
jump of 0.060V when the 4870 1GB enters 3D mode.

ATI HD 4870 1GB: BIOS Fan settings.

The fan control behavior follows a simple linear progression starting at a
GPU temperature of 58°C and finishing at 101°C.

Asus HD 4870 512MB Matrix: BIOS Clock/voltage settings.

The Matrix’s BIOS shows the voltages locked at 1.263V — you’re expected
to use iTracker if you want any power savings. The fan control panel was greyed
out, so we still have no insight into the how the card’s main fan operates.


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.

These recordings are intended to give you an idea of how the product sounds
in actual use — one meter is a reasonable typical distance between a computer
or computer component and your ear. The recording contains stretches of ambient
noise that you can use to judge the relative loudness of the subject. Be aware
that very quiet subjects may not be audible — if we couldn’t hear it from
one meter, chances are we couldn’t record it either!

The recording starts with 5~10 seconds of room ambiance, followed by 5~10 seconds
of the VGA test system without a video card installed, and then the actual product’s
noise at various levels. As this particular card did not add any noise the test
system, we have provided only a recording of the test system with its system
fan set to the levels tested. 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.


Gaming: Please check out gaming-oriented reviews of the ATI HD 4870 at techPowerUp,
The Tech Report,
and Anandtech.
The general consensus is that the HD 4870 performance is on par with the pricier GeForce GTX 260. A 512MB version like the Matrix will deliver excellent
frame rates on the majority of PC titles if played at 1680×1050 resolution or
lower. It does a passable job at higher resolutions, though a 1GB model would
be better in this regard.

Cooling/Noise: The Asus 4870 Matrix cooler was a big disappointment. It kept the GPU
cooler than the reference ATI cooler, but the minimum
speed of both fans was too high. One fan cannot be controlled at all, while the
other can only be turned off or set to spin even faster! At first we were amazed
at how quiet the card was… until we realized neither fan was spinning and the
GPU temperature was increasing steadily. Eventually the main fan turned itself
on, then off again, repeating ad nauseum in an inane cycle. The reference cooler by comparison
was very quiet — its noise level during load was equal to the Matrix
when idle, at least during the “fan on” portion of its cycle.

Power: By our estimates, the HD 4870 Matrix requires about
48W idle in Power Saving mode and up to 140W when stressed to the limit if used
with the overclocked Optimized/Gaming profile. This is the highest power draw we’ve measured on any graphics card thus far, exceeding the both the reference ATI HD 4870 1GB card and the Asus
by a small margin.

The Asus HD 4870 Matrix left us with mixed reactions. The amount of frequency
and voltage customization provided by Asus’ iTracker utility is truly impressive
— it gives enthusiasts unparalleled control to maximize the card’s performance
in 3D mode while minimizing its power consumption when idle. Overshadowing this
incredible feature is the dismal fan control implementation. The noise generated
is also amplified by the fans’ undesirable acoustic characteristics. If faced with
a choice, we would pick the reference ATI cooler over the Matrix cooler. Recent ATI price drop makes HD 4870 cards the best value in mid-range
performance graphics, but the premium charged for the Asus Matrix is difficult to justify. We certainly hope the iTracker utility is impelemted in a card that’s better implemented, acoustically speaking — nicer sounding fans, and better fan control. Meanwhile, perhaps Asus can correct basic fan control problems with a firmware update to the card.

Asus EAH4870 MATRIX /HTDI/512MD5
* Excellent core GPU control
* Excellent 3D performance
* Main fan cycles on / off
* Fans too noisy at any setting

Our thanks to ASUSTeK
for the video card sample.

* * *

Articles of Related Interest
PowerColor SCS HD4650: A Fanless
Budget Graphics Card

EN9800GT Matrix

the Gap: ATI Radeon HD 4830

Redefining Budget Gaming Graphics: ATI’s
HD 4670

Asus ENGTX260: A Quiet Graphics
Card for Gamers?

Diamond Radeon HD4850

* * *

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