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ATI Radeon HD 4830 Mainstream GPU
Date: Oct 23, 2008
Author: Marco Chiappetta
Introduction and Specifications

Since the RV770 GPU's initial arrival, we have seen the technology used in the GPU migrate up and down AMD's product stack. At first, the RV770 powered only the ATI Radeon HD 4850 and 4870, but soon thereafter two RV770's were linked together to form the current flagship Radeon HD 4870 X2.  Then the GPU was scaled down to bring out the Radeon HD 4600, 4500, and 4300 series of products. Ultimately, AMD ended up with competitive offerings at virtually every price point, ranging from $39 on up, to over $550 for the flagship product. But there is an approximate $80 price gap between the $160-ish Radeon HD 4850 and the roughly $80 Radeon HD 4670, that AMD plans to fill today with the release of the Radeon HD 4830.

As its name suggests, this latest addition to the Radeon HD 4800 series is similar to the Radeon HD 4850. In fact, the reference designs look almost identical. The 4830 however, has had a couple of SIMD arrays disabled, and hence has fewer active stream processors and TMUs.  We'll show you what other differences there are a little later.  For now, check out the specs and other related information.  We'll get on with the show right afterwards...

ATI Radeon HD 4830

AMD ATI Radeon HD 4830
Specifications and Features

  • 956 million transistors on 55nm fabrication process
  • PCI Express 2.0 x16 bus interface
  • 256-bit GDDR3/GDDR5 memory interface
  • Microsoft DirectX 10.1 support
    • Shader Model 4.1
    • 32-bit floating point texture filtering
    • Indexed cube map arrays
    • Independent blend modes per render target
    • Pixel coverage sample masking
    • Read/write multi-sample surfaces with shaders
    • Gather4 texture fetching
  • Unified Superscalar Shader Architecture
    • 800 stream processing units
      • Dynamic load balancing and resource allocation for vertex, geometry, and pixel shaders
      • Common instruction set and texture unit access supported for all types of shaders
      • Dedicated branch execution units and texture address processors
    • 128-bit floating point precision for all operations
    • Command processor for reduced CPU overhead
    • Shader instruction and constant caches
    • Up to 160 texture fetches per clock cycle
    • Up to 128 textures per pixel
    • Fully associative multi-level texture cache design
    • DXTC and 3Dc+ texture compression
    • High resolution texture support (up to 8192 x 8192)
    • Fully associative texture Z/stencil cache designs
    • Double-sided hierarchical Z/stencil buffer
    • Early Z test, Re-Z, Z Range optimization, and Fast Z Clear
    • Lossless Z & stencil compression (up to 128:1)
    • Lossless color compression (up to 8:1)
    • 8 render targets (MRTs) with anti-aliasing support
    • Physics processing support
  • Dynamic Geometry Acceleration
    • High performance vertex cache
    • Programmable tessellation unit
    • Accelerated geometry shader path for geometry amplification
    • Memory read/write cache for improved stream output performance
  • Anti-aliasing features
    • Multi-sample anti-aliasing (2, 4 or 8 samples per pixel)
    • Up to 24x Custom Filter Anti-Aliasing (CFAA) for improved quality
    • Adaptive super-sampling and multi-sampling
    • Gamma correct
    • Super AA (ATI CrossFireX configurations only)
    • All anti-aliasing features compatible with HDR rendering
  • Texture filtering features
    • 2x/4x/8x/16x high quality adaptive anisotropic filtering modes (up to 128 taps per pixel)
    • 128-bit floating point HDR texture filtering
    • sRGB filtering (gamma/degamma)
    • Percentage Closer Filtering (PCF)
    • Depth & stencil texture (DST) format support
    • Shared exponent HDR (RGBE 9:9:9:5) texture format support
  • OpenGL 2.0 support

 ATI PowerPlay

  • Advanced power management technology for optimal performance and power savings
  • Performance-on-Demand
    • Constantly monitors GPU activity, dynamically adjusting clocks and voltage based on user scenario
    • Clock and memory speed throttling
    • Voltage switching
    • Dynamic clock gating
  • Central thermal management – on-chip sensor monitors GPU temperature and triggers thermal actions as required

ATI Avivo HD Video and Display Platform

  • 2nd generation Unified Video Decoder (UVD 2)
    • Enabling hardware decode acceleration of H.264, VC-1 and MPEG-2
    • Dual stream playback (or Picture-in-picture)
  • Hardware MPEG-1, and DivX video decode acceleration
    • Motion compensation and IDCT
  • ATI Avivo Video Post Processor
    • New enhanced DVD upconversion to HD new!
    • New automatic and dynamic contrast adjustment new!
    • Color space conversion
    • Chroma subsampling format conversion
    • Horizontal and vertical scaling
    • Gamma correction
    • Advanced vector adaptive per-pixel de-interlacing
    • De-blocking and noise reduction filtering
    • Detail enhancement
    • Inverse telecine (2:2 and 3:2 pull-down correction)
    • Bad edit correction
    • Full score in HQV (SD) and HQV (HD) video quality benchmarks
  • Two independent display controllers
    • Drive two displays simultaneously with independent resolutions, refresh rates, color controls and video overlays for each display
    • Full 30-bit display processing
    • Programmable piecewise linear gamma correction, color correction, and color space conversion
    • Spatial/temporal dithering provides 30-bit color quality on 24-bit and 18-bit displays
    • High quality pre- and post-scaling engines, with underscan support for all display outputs
    • Content-adaptive de-flicker filtering for interlaced displays
    • Fast, glitch-free mode switching
    • Hardware cursor
  • Two integrated DVI display outputs
    • Primary supports 18-, 24-, and 30-bit digital displays at all resolutions up to 1920x1200 (single-link DVI) or 2560x1600 (dual-link DVI)
    • Secondary supports 18-, 24-, and 30-bit digital displays at all resolutions up to 1920x1200 (single-link DVI only)3
    • Each includes a dual-link HDCP encoder with on-chip key storage for high resolution playback of protected content4
  • Two integrated 400MHz 30-bit RAMDACs
    • Each supports analog displays connected by VGA at all resolutions up to 2048x15363
  • DisplayPort output support
    • Supports 24- and 30-bit displays at all resolutions up to 2560x16003
  • HDMI output support
    • Supports all display resolutions up to 1920x10803
    • Integrated HD audio controller with up to 2 channel 48 kHz stereo or multi-channel (7.1) AC3 enabling a plug-and-play cable-less audio solution
  • Integrated AMD Xilleon HDTV encoder
    • Provides high quality analog TV output (component/S-video/composite)
    • Supports SDTV and HDTV resolutions
    • Underscan and overscan compensation
    • MPEG-2, MPEG-4, DivX, WMV9, VC-1, and H.264/AVC encoding and transcoding
    • Seamless integration of pixel shaders with video in real time
    • VGA mode support on all display outputs
  • ATI CrossFireX Multi-GPU Technology
    • Scale up rendering performance and image quality with two GPUs
    • Integrated compositing engine
    • High performance dual channel bridge interconnect

As the above list of specifications and features show, the new Radeon HD 4830 has essentially the exact same features as the other cards in the Radeon HD 4800 series.  The Radeon HD 4830 offers DX10.1 and Shader Model 4.1 support, AVIVO HD, HDMI with audio, etc.  These GPUs are manufactured on TSMC's 55nm process node and the cards support ATI's CrossFireX multi-GPU technology.

Since we've covered essentially all of the shared features of the Radeon HD 4800 series cards before, we won't go into them in depth again here.  However, we would recommend taking a look at a few of our recent articles to brush up on the tech, if you're so inclined.

Reading the articles above will lay the groundwork for much of what we'll be showing you on the pages ahead.  Because the new Radeon HD 4830 shares the same GPU as the other cards in the Radeon HD 4800 series, with some elements disabled, they have the same feature set and capabilities but differentiate in terms of performance.

A Closer Look At The Cards

To illustrate exactly how the new Radeon HD 4830 differs from the Radeon HD 4850 and HD 4870 that preceded it in terms of specifications, we've got a simple chart that outlines the main differences between the cards.


As you can see, the Radeon HD 4830 differs from its 4800 series counterparts only in its number of stream processors, texture units, and clock speeds.  Two of the RV770 GPU's 10 SIMD arrays and associated texture units have been disabled, which results in a total of 640 active stream processors--down from 800 in the Radeon HD 4850.  The Radeon HD 4830's core clock has also been lowered a bit, to 575MHz.  The result is less compute performance and fillrate.  Memory bandwidth is down as well, but that's only because of a clock speed reduction, as the Radeon HD 4830 has the same memory bus width.  Another interesting aspect of the list above is max board power.  AMD is rating the cards at a maximum of 110W, just like the 4850.  Convention wisdom suggests power consumption would be lower, but AMD is being conservative here because they are binning more chips from a die and may need to goose the voltage on some of them to reach the desired specs.

ATI Radeon HD 4830 Reference Card

There's nothing much new to see here physically.  AMD's reference ATI Radeon HD 4830 looks exactly like a Radeon HD 4850.  We were informed, however, that most board partners would be offering non-reference Radeon HD 4830s that use different PCBs, coolers, memory, etc.  And that seems to be true as evidenced below...



PowerColor Radeon HD 4830

The PowerColor Radeon HD 4830 is completely different from AMD's reference design.  The card has a shorter PCB (by about an inch), custom dual-slot cooling, and a unique assortment of outputs.  In lieu of a TV output and second DVI connector, this card sports an analog DB15 VGA connector and a DisplayPort.  Also, remember that these cards support HDMI output with audio when used with the correct DVI-to-HDMI dongle.

The specifications on PowerColor's offering are identical to the reference design with a 575MHz core clock and 512MB of 900MHz GDDR3 memory.  PowerColor's cooler, however, performed better.  Whereas the reference card would peak with an approximate 82'C GPU temp under load, the PowerColor Radeon HD 4830 never broke 76'C.  Both remained very quiet during testing.

Test Systems and 3DMark06

HOW WE CONFIGURED THE TEST SYSTEMS: We tested all of the graphics cards used in this article on either an Asus nForce 790i SLI Ultra based Striker II Extreme motherboard (NVIDIA GPUs) or an X48 based Asus P5E3 Premium (ATI GPUs) powered by a Core 2 Extreme QX6850 quad-core processor and 2GB of low-latency Corsair RAM. The first thing we did when configuring these test systems was enter their respective BIOSes and set all values to their "optimized" or "high performance" default settings. Then we manually configured the memory timings and disabled any integrated peripherals that wouldn't be put to use. The hard drive was then formatted, and Windows Vista Ultimate was installed. When the installation was complete we fully updated the OS, and installed the latest DX10 redist and various hotfixes, along with the necessary drivers and applications.

HotHardware's Test Systems
Intel and NVIDIA Powered

Hardware Used:
Core 2 Extreme QX6850 (3GHz)

Asus Striker II Extreme
(nForce 790i SLI Ultra chipset)

Asus P5E3 Premium
(X48 Express)

Radeon HD 4830
Radeon HD 4850
Radeon HD 4670
GeForce 9500 GT
GeForce 9600 GT
GeForce 9800 GT

2048MB Corsair DDR3-1333 C7
(2 X 1GB)

Integrated Audio
Integrated Network

Western Digital "Raptor" 74GB
(10,000RPM - SATA)

Relevant Software:

Windows Vista Ultimate SP1
DirectX June 2008 Redist

NVIDIA Forceware v178.13
ATI Catalyst v8.54

Benchmarks Used:
3DMark06 v1.0.2
3DMark Vantage v1.0.1
Unreal Tournament 3 v1.2*
Crysis v1.2*
Half Life 2: Episode 2*
Enemy Territory: Quake Wars*

* - Custom Benchmark

Futuremark 3DMark06
Synthetic DirectX Gaming


3DMark06 is a synthetic benchmark, designed to simulate DX9-class game titles. This version differs from the earlier 3Dmark05 in a number of ways, and includes not only Shader Model 2.0 tests, but Shader Model 3.0 and HDR tests as well. Some of the assets from 3DMark05 have been re-used, but the scenes are now rendered with much more geometric detail and the shader complexity is vastly increased. Max shader length in 3DMark05 was 96 instructions, while 3DMark06 ups that number to 512. 3DMark06 also employs much more lighting and there is extensive use of soft shadows. With 3DMark06, Futuremark has also updated how the final score is tabulated. In this latest version of the benchmark, SM 2.0 and HDR / SM3.0 tests are weighted and the CPU score is factored into the final tally as well.

A quick note about our benchmark results before we go any further.  We've included Radeon HD 4830 CrossFire scores for reference, but please note that there are no other dual-GPU configurations listed.  We've included the CrossFire scores because we know many of you would be interested in how a pair of these affordable cards stackes up.

With that said, the Radeon HD 4830 performed just as expected in 3DMark06--faster than the Radeon HD 4670, but not quite as fast as the more powerful 4850.



The results from 3DMark06's individual sub-tests mirror the overall result.  The Radeon HD 4830 falls in between the 4670 and 4850.

3Dmark Vantage

Futuremark 3DMark Vantage
Synthetic DirectX Gaming

3DMark Vantage

The latest version of Futuremark's synthetic 3D gaming benchmark, 3DMark Vantage, is specifically bound to Windows Vista-based systems because it uses some advanced visual technologies that are only available with DirectX 10, which y isn't available on previous versions of Windows.  3DMark Vantage isn't simply a port of 3DMark06 to DirectX 10 though.  With this latest version of the benchmark, Futuremark has incorporated two new graphics tests, two new CPU tests, several new feature tests, in addition to support for the latest PC hardware.  We tested the graphics cards here with 3DMark Vantage's Performance preset option, which uses a resolution of 1280x1024, with no anti-aliasing or anisotropic filtering.


The 3DMark Vantage overall score, as reported by the "Performance" preset, essentially mirror those from 3DMark06 on the previous page, albeit with wider performance deltas.  The trend remains the same.



3DMark Vantage's individual GPU tests show a similar trend the overall result above and to each other, with the Radeon HD 4830 falling in between the 4670 and 4850.

Half Life 2: Episode 2

Half Life 2: Episode 2
DirectX Gaming Performance

Half Life 2:
Episode 2

Thanks to the dedication of hardcore PC gamers and a huge mod-community, the original Half-Life was one of the most successful first person shooters of all time. And courtesy of an updated game engine, gorgeous visuals, and intelligent weapon and level designs, Half Life 2 became just as popular.  Episode 2 - the most recent addition to the franchise - offers a number of visual enhancements including better looking transparent texture anti-aliasing. These tests were run at resolutions of 1,280 x 1,024 and 1,680 x 1,050 with 4X anti-aliasing and 16X anisotropic filtering enabled concurrently.  Color correction and HDR rendering were also enabled in the game engine as well.  We used a custom recorded timedemo to benchmark all cards for these tests.


The Radeon HD 4830 performed very well in our custom Half Life 2 benchmark.  The performance trend we've seen on the preceding pages essentially played out again, but for a card of this type, the framerates are quite good.

Unreal Tournament 3

Unreal Tournament 3
DirectX Gaming Performance

Unreal Tournament 3

If you're a long-time PC gamer, the Unreal Tournament franchise should need no introduction.  UT's fast paced action and over the top weapons have been popular for as long as Epic has been making the games.  For these tests, we used the latest addition to the franchise, Unreal Tournament 3.  The game doesn't have a built-in benchmarking tool, however, so we enlisted the help of FRAPS here.  These tests were run at resolutions of 1,280 x 1,024 and 1,680 x 1,050 with no anti-aliasing or anisotropic filtering enabled, but with the UT3's in game graphical options set to their maximum values, with color correction enabled.


The Radeon HD 4830 put up good numbers in our custom UT3 benchmark as well. The previous performance trend remained the same, but the framerates were again very good for a card in this market segment.

Enemy Territory: Quake Wars

Enemy Territory: Quake Wars
OpenGL Gaming Performance

Enemy Territory:
Quake Wars

Enemy Territory: Quake Wars is Based on a radically enhanced version of id's Doom 3 engine and viewed by many as Battlefield 2 meets the Strogg, and then some.  In fact, we'd venture to say that id took EA's team-based warfare genre up a notch or two.  ET: Quake Wars also marks the introduction of John Carmack's "Megatexture" technology that employs large environment and terrain textures that cover vast areas of maps without the need to repeat and tile many smaller textures.  The beauty of megatexture technology is that each unit only takes up a maximum of 8MB of frame buffer memory.  Add to that HDR-like bloom lighting and leading edge shadowing effects and Enemy Territory: Quake Wars looks great, plays well and works high end graphics cards vigorously.  The game was tested with all of its in-game options set to their maximum values with soft particles enabled in addition to 4X anti-aliasing and 16x anisotropic filtering.


In our custom Enemy Territory Quake Wars benchmark, the Radeon HD 4830 performed very well, hanging with the Radeon HD 4850 and GeForce 9800, and easily surpassing the HD 4670 and 9600 GT.

Crysis Performance

Crysis v1.2
DirectX 10 Gaming Performance


If you're at all into enthusiast computing, the highly anticipated single player, FPS smash-hit Crysis, should require no introduction. Crytek's game engine produces some stunning visuals that are easily the most impressive real-time 3D renderings we've seen on the PC to date.  The engine employs some of the latest techniques in 3D rendering like Parallax Occlusion Mapping, Subsurface Scattering, Motion Blur and Depth-of-Field effects, as well as some of the most impressive use of Shader technology we've seen yet.  In short, for those of you that want to skip the technical jib-jab, Crysis is a beast of a game.  We ran the full game patched to v1.2 with all of its visual options set to 'Medium' to put a significant load on the graphics cards being tested  A custom demo recorded on the Island level was used throughout testing.


The Radeon HD 4830 was a strong performer in Crysis as well.  The Radeon HD 4850 pulled away by a more significant margin that we saw in some other tests, and CrossFire didn't seem to scale properly, but the 4830 broke the 60FPS mark at 1280 with medium settings.

SD and HD Video Performance

We also did some quick testing of the new Radeon HD 4830's video processing engine, in terms of both image quality and CPU utilization with some standard and high-definition video playback tests.

Video Playback Performance: SD and HD
HQV (coming soon) and H.264

HQV is comprised of a sampling of SD video clips and test patterns that have been specifically designed to evaluate a variety of interlaced video signal processing tasks, including decoding, de-interlacing, motion correction, noise reduction, film cadence detection, and detail enhancement. As each clip is played, the viewer is required to "score" the image based on a predetermined set of criteria. The numbers listed below are the sum of the scores for each section. We played the HQV DVD using the latest version of Cyberlink's PowerDVD HD, with hardware acceleration for AMD AVIVO HD and NVIDIA PureVideo HD extensions enabled.

Both ATI's and NVIDIA's latest GPUs have no trouble with SD video playback. All three of the cards put up near perfect scores in the HQV test. In case you're not familiar with HQV, 130 points is the maximum score attainable. At 128 points, a PC equipped with any of these graphics cards plays back DVD video at quality levels better than the vast majority of set-top DVD players on the market.

Next we conducted a test using an H.264 encoded movie which is available for download on NASA's HD gallery website.  The CPU utilization data gathered during these tests was taken from Windows Vista's built-in Performance Monitor. The graphs show the CPU utilization for a GeForce 9500 GT and a Radeon HD 4830 using PowerDVD 8 Ultra to playback the QuickTime clip.

GeForce 9500 GT

Radeon HD 4830

With a fast quad-core processor powering our test system and an unencrypted HD video clip being played back, both of the cards we tested had low CPU utilization in this test.  We should note that with hardware acceleration disabled, playing this video clip results in about 12% - 15% average CPU utilization, so there is a marked improvement with both PureVideo HD and UVD 2.  Also note that with encrypted content, like many off the shelf Blu-Ray discs for example, CPU utilization will be measurably higher that what you see here.  However, both platforms should have no trouble playing back HD digital video.

Total System Power Consumption

We'd like to cover a few final data points before bringing this article to a close. Throughout all of our benchmarking and testing, we monitored how much power our test systems were consuming using a power meter. Our goal was to give you an idea as to how much power each configuration used while idling and under a heavy workload. Please keep in mind that we were testing total system power consumption at the outlet here, not just the power being drawn by the motherboards alone.

Total System Power Consumption
Tested at the Outlet

Although AMD rates the ATI Radeon HD 4830 with the same max board power as the HD 4850 (110W), our particular sample consumed less power at both idle and under load.  AMD noted this may not be the case with every HD 4830 though, so be aware there will be differences from card to card.

Our Summary and Conclusion

Performance Summary: The new ATI Radeon HD 4830 performed right in line with its position in the market--the card was clearly faster than the more affordable Radeon HD 4670 and a bit slower than the pricer Radeon HD 4850.  In comparison to NVIDIA's offerings, the 4830 is typically faster than the GeForce 9600 and about on par with or somewhat slower than a GeForce 9800 GT.  In comparing the reference card to PowerColor's, even though they shared the same specifications, the PowerColor Radeon HD 4830, was usually a bit faster than the reference card, probably due to slight tweaks associated with the shorter board design.


With an expected street price of around $129 (some boards are already available for $119 after mail in rebates), the Radeon HD 4830 seems to be a solid product.  If you want an affordable, no compromise graphics solution that can handle all of today's games and virtually any video decoding task, the Radeon HD 4830 should fit the bill nicely.  Be aware, however, that the sub-$150 graphics card space is loaded, perhaps overloaded, with worthwhile products currently, so you could save a few bucks and get something with only slightly lower performance or spent just a few dollars more and get something faster. In a few weeks / months time, as older models undergo further price cuts or disappear from shelves altogether, there should be cleared differentiation in the market.  So for now, just be extra diligent when shopping to ensure you're getting the best deal.  If you don't feel like comparison shopping though, and the Radeon HD 4830's price is right, we doubt anyone would be disappointed in this card.  The Radeon HD 4830 represents a great value for the money.

Update: A representative from AMD gave us a call shortly after the launch of this article to let us know that a certain percentage of Radeon HD 4830 cards are equipped with an incorrect BIOS that disables an additional SIMD core.  Our reference card was one of those affected, but the PowerColor card was not.  The bad BIOS explains the performance discrepancy between the two cards, despite their having the same specifications.  AMD has supplied us with a new BIOS for the reference Radeon HD 4830 and it is now performing on-par with the PowerColor card.

  • Great Value
  • Good Performance
  • CrossFireX Support
  • Runs Fairly Hot
  • Muddled Market Space

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