Filling the Gap: ATI Radeon HD 4830

The 4000 series video cards is one of ATI’s most successful, and also one of the most wide-ranging. There’s the HD 4870 X2 at the top — widely lauded as the current performance graphics champ — followed by the 4870 and 4850. With the HD 4670 at $80 and the HD 4850 at $170, it was logical for ATI to fill the price gap. At $130, the HD 4830 looks to follow in the tradition of its brethren and represent very good value.

October 26, 2008 by Lawrence Lee

In these trying economic times, it’s hard to justify the cost of a high performance
graphics card — especially when you consider that video cards are superceded at least once every half year, and
subject to the law of diminishing returns — the more you pay, the less increase
in performance you get. For those who are financially conservative, the
object of our desire is the best product for the price, or colloquially, the
best bang-for-your-buck.

Earlier this year, ATI released the HD
4850, an excellent card at an excellent price. It offered so much value
that in reaction, nVidia immediately lowered the price on their Geforce 9800
GTX, and then quickly pushed out the improved 9800 GTX+. The 4000 series is one of ATI’s most successful in recently memory, and also one of the most wide-ranging. There’s the HD 4870 X2 at the top — widely lauded as the best performance graphics card on the market — followed by the 4870 and 4850. With the HD 4670 going
for $80 and the HD 4850 for $170, it was logical for ATI to fill the price gap. At $130, the HD 4830 looks to follow in
the tradition of its brethren and represent very good value.

The HD 4830 is essentially a cut-down version of the
HD 4850. Its core and memory speeds have been reduced and it features only 640
stream processing units down from 800. These small differences shouldn’t affect
performance too much but it should be easier to cool and consume less power
than the HD 4850.

PHYSICAL DETAILS & INSTALLATION

Our HD 4830 sample came straight from ATI with no packaging of any kind. When
shopping for a HD 4830, check the specifications carefully — manufacturers
do not always follow the reference design, so different HD 4830’s may have different
video outputs, clock/memory speeds, memory type, and coolers.

The HD 4830 looks identical to the HD 4850 and HD 3850. The same heatsink is utilized and the PCB is more or less the same length at 23.3cm.

TEST METHODOLOGY

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, bluescreen 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 lifespan 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

• Intel
  Pentium D 930 Presler core processor. Official TDP of 95W.
• AOpen
  i945Ga-PHS motherboard – Intel i945Ga Chipset; built-in VGA.
• Gigabyte G-Power 2 Pro
  heatsink, modified with a Scythe
  Slip Stream 500RPM 120mm fan.
• Corsair
  DDR2 RAM, PC2-6400, 1024 MB
• Seagate Momentus 5400.3
  160 GB, 5400RPM, ATA/100, 2-platter notebook hard drive, suspended
• Seasonic S12-600
  ATX12V v2.0 compliant power supply, modified with a Scythe
  Slip Stream 800RPM 120mm fan @ 5V.
• Antec P180B case,
  modified in detail below.
• Nexus 120mm
  fan connected to a variable fan speed controller.
• Microsoft
  Windows XP Professional operating system
• QuickTime
  Alternative 1.81 codec package

Further details can be found in our Updated VGA Card/Cooler Test Platform article.

Measurement and Analysis Tools

• CPUBurn
  P6 to stress the CPU
• ATITool
  version 0.27 Beta 4 as a tool for stressing the GPU
• FurMark 1.4 as
  a tool for stressing the GPU
• GPU-Z 0.2.8
  to show the GPU temperature and fan speed
• SpeedFan
  version 4.33 to show CPU temperature
• Cyberlink
  PowerDVD 7.3 to play video.
• 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
  fan
• 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 ATITool (or
just SpeedFan if a nVidia based card is used) during different states: Idle,
with CPUBurn running to stress the processor, and with CPUBurn and ATITool’s
artifact scanner (or 3D View, which produces even 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. We also use FurMark
as an alternative GPU stress utility. The software is left running until the
GPU temperature stabilizes for at least 10 minutes. If artifacts are detected
or other instability is noted, the heatsink is deemed inadequate to cool the
video card in our test system.

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.

Video Playback Testing

For our second test, we play a variety of video clips with PowerDVD. A CPU
usage graph is created via the Windows Task Manger for analysis to determine
the approximate mean and peak CPU usage. If the card (in conjunction with the
processor) is unable to properly decompress the clip, the video will skip or
freeze, often with instances of extremely high CPU usage as the system struggles
to play it back. High CPU usage is undesirable as it increases power consumption,
and leaves fewer resources for background tasks and other applications that
happen to be running during playback. Power draw is also recorded during playback.

Video Test Suite

1920×816 | 24fps | ~10mbps

H.264: Rush Hour 3 Trailer 1 is encoded with H.264. It has a good mixture of light and dark scenes, interspersed with fast-motion action and cutaways.

1440×1080 | 24fps | ~8mbps

WMV3: Coral Reef Adventure trailer is encoded in VC-1 using the WMV3 codec (commonly recognized by the moniker, “HD WMV”). It features multiple outdoor landscape and dark underwater scenes.

1280×720 | 60fps | ~12mbps

WVC1: Microsoft Flight Simulator X trailer is encoded in VC-1. It’s a compilation of in-game action from a third person point of view. 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 features a high-paced drag race. It is the most demanding clip in our test suite.

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)	65.3	89.7	148.7	198.5	249.5	300.2
AC Input (W)	87.0	115.0	183.1	242.1	305.0	370.2
Efficiency	75.1%	78.0%	81.2%	82.0%	81.8%	81.1%

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.

TEST RESULTS

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.

Note: In our hemi-anechoic chamber, our VGA test bed now
measures 12 dBA@1m. Ambient noise is only 11 dBA.

ATI RADEON HD 4830:

At idle, the fan spun at only 1850 RPM according to GPU-Z. The GPU temperature
was an acceptable 55°C and system AC power draw was modest. When the system
was stressed with both CPUBurn and ATITool, the GPU temperature gradually increased,
until at 75°C, the fan speed finally began to ramp up. After
twenty minutes, the fan speed reached between 5400 and 5600 RPM — it vacillated
throughout this range continuously while the GPU temperature stayed at about
85°C. Running FurMark in place of ATITool squeezed a few extra watts out
of the system’s power draw. The system reached a peak power consumption of 246W,
a stark contrast to the extremely frugal HD
4670 we tested last.

At idle the SPL was 14 dBA@1m which is only 2 dBA higher
than the test system without a discrete video card installed. While the reading was quite
low, the fan emitted a slightly high pitched whine, but this could only be heard
when the card was exposed. Once the side panel of our P182 case was in place,
it all but vanished. At distances of half a meter or more, it was basically
inaudible. At load, the fan was noticeably louder and exhibited undesirable
tonality. In addition, the fan would not settle at a single speed, creating
a droning effect as it shifted between 5400 and 5600 RPM. It was enough change
that it was recorded by our instruments — the noise kept cycling continuously between 20 and 21 dBA.
The measured level may seem low, yet subjectively, it’s plainly audible from a meter away. This cyclical variability is more annoying than the overall noise level itself. We found
no way of controlling the fan manually — neither through ATITool or RivaTuner.

It should also be noted that the coil whine that plagues so many modern graphics
cards also affects the HD 4830. It is especially evident when running ATITool’s
artifact tester and 3DView.

Sensors according to GPU-Z during CPUBurn + Furmark.

POWER

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 on our test system. 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 system power under CPUBurn with just the integrated graphics is subtracted from the system power under CPUBurn with the add-on card, we obtain the increase in idle power of the add-on card. (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 ATITool
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 ATITool
should not skew the results, since the CPU was running at full load in both
system. Recently we have been using the Furmark utility in place of ATITool
as it has been found to increase power consumption more than ATITool. As many
of our previous results were obtained using ATITool, we have opted to test with
both programs to keep older comparisons more accurate.

By our measurements the HD 4830 used a modest amount of power at idle —
18W, which is closer to the HD
3870 than the HD 4850. The HD 4850 seemed to have had
malfunctioning power management when it was tested — we’re not sure if
this is still the case. Load power was 11% higher than the HD 3870, but 21%
lower than the HD 4850. Unless the HD 4830’s efficiency is extremely low or
high, its 3D performance should lay somewhere in between these two cards.

PowerPlay, ATI’s power management technology seemed to be working on the HD
4830 as the idle power measurement was fairly low. Also, according to GPU-Z,
when idle and during video playback the core and memory speeds stayed underclocked
at 160/250Mhz. Only when ATITool or FurMark was running did the clock speeds
rise to its maximum 575/900Mhz.

Video Playback

The HD 4830 handled our video playback testbed with ease. CPU usage during
playback failry low except for our more demanding VC-1 clips. The H.264 Rush
Hour 3 trailer had a trivial effect on system resources.

In terms of CPU usage, video playback was very similar to the previous Radeons.
Power consumption during video playback were at levels in-between the HD 4850
and HD 3870, just as they were during idle and full load.

MP3 SOUND RECORDINGS

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 10 seconds of room ambience, followed by 10 seconds
of the VGA test system without a video card installed, and then the actual product’s
noise at various levels. 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.

• ATI
  Radeon HD 4830 stock fan at one meter
  — idle (14 dBA@1m)
  — load (20-21 dBA@1m)

Comparison

• ATI
  Radeon HD 4670 stock fan at one meter
  — idle (13 dBA@1m)
  — load (16 dBA@1m)
  — 60% (21 dBA@1m)
  — 100% (26 dBA@1m)

FINAL THOUGHTS

Gaming: Please check out the gaming-oriented reviews at AnandTech,
The
Guru of 3D, The Tech Report, and TechPowerUp.
The general consensus is that the performance of the HD 4830 is in-between the Geforce 9800GT and
9800GTX+. Its aggressive price makes it a great value
card for playing the latest 3D games at 1680×1050 or 1600×1200 resolution.

Video Playback: Video playback was very good. The decoding hardware has
not changed from the previous HD 4000 series cards.

Cooling: The stock cooler is an average performer —
it kept the GPU at adequate temperatures (55°C idle and 85°C load).
When idle, the noise level was good and its nastier attributes were all
but muffled once installed in a system with the side cover in place. At full
load, it was very noisy by our standards — typical for most graphics cards.
However, more bothersome than the overall noise level was the fact that
the fan controller could not settle on one speed, resulting in a rhythmic
pulsing as the fan alternated between higher and lower speed. As usual, it has to be mentioned that for gamers who like their sound effects, this aural annoyance may well be masked by game sound effects.

Power Consumption: By our estimates, the HD 4830 requires approximately
18W when idle and up to 87W when stressed to the limit — this is a vast improvement
over the HD 4850 due to its broken power management (50W idle). Its power consumption
more closely resembles the HD 3870, though it performs closer to its big brother,
the HD 4850. It’s nice to see ATI get it right from the start this time around.

In our opinion, the HD 4830 represents the best middle-of-the-road graphics
card for those who want to have a good gaming experience without breaking the
bank or driving up the electric bill. It’s not one of those revolutionary cards
that crushes the competition and redefines value, but it performs well
and is priced aggressively — enough to push the Geforce 9800GT completely
out of the picture. Our main complaint is the stock reference cooler
and its poor fan qualities. If you only need it to be quiet at idle, it’s a
fine card, but once you start to push it, the noise level goes up while the its quality goes down. Luckily it has the same PCB and mounting hole
design as its predecessors, so most third party heatsinks are compatible.

Our thanks to ATI
for the video card sample.

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Articles of Related Interest
Redefining Budget Gaming Graphics:
ATI’s HD 4670
Asus ENGTX260: A Quiet Graphics
Card for Gamers?
Diamond Radeon HD4850
Asus EN3650 Silent Graphics
Card
Asus EN9600GT Silent Edition
Graphics Card
ATI HD 3850 & HD 3870: Improved
Acoustics & Power Efficiency

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