ATI Radeon HD 4850 and 4870: RV770 Has Arrived - HotHardware

ATI Radeon HD 4850 and 4870: RV770 Has Arrived

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Last week, due to some unexpected circumstances, we were able to post a sneak peek of the RV770 GPU and ATI Radeon HD 4850 graphics card.  As our limited testing showed, the Radeon HD 4850 was quite promising for a $199 graphics card.  But we weren't able to tell the complete story.  While the initial benchmarks definitely looked good, there was a lot more to talk about in regard to the Radeon HD 4850 and the RV770 GPU at the heart of the card.

Today we can finally spill the rest of the beans.  You see, AMD didn't plan to officially announce just one new Radeon HD 4800 series card this week, but two, with a dash of information about a third thrown in for good measure.  Today marks the official arrival of not only the Radeon HD 4850, but the higher-end Radeon HD 4870 as well.  As we've already explained, one card - the Radeon HD 4850 - is targeted at the sub-$200 price point.  The other, however, is a $299 screamer that makes use of some cutting edge technology, like GDDR5 memory.

We'll get down to the nitty gritty just a little later. For now, check out the list of features and specifications below and strap in for an exciting ride.  What we have in store, may surprise some of you...



ATI Radeon HD 4850 (RV770)
 

AMD ATI Radeon HD 4800 Series
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 4800 series has much in common with the Radeon HD 3800 series.  Both offer DX10.1 and Shader Model 4.1 support, both series of GPUs are manufactured on TSMC's 55nm process node, and both support ATI's CrossFireX multi-GPU technology.

    Because we've covered many of the shared features of the Radeon HD 4800 and 3800 series cards before, we won't be going in depth again here.  However, we would recommend taking a look at a few recent articles to brush up on the tech if you're so inclined.

    Perusing the sampling of articles above will lay the groundwork for much of what we'll be showing you on the pages ahead.

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     Hi All.  If you liked this article, please Digg it...

    http://digg.com/hardware/ATI_Radeon_HD_4850_and_4870_RV770_is_Here_CrossFire_Tested

    Thanks!

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    Aside from the heat output this definately sounds like a better buy (the 4870) than does the GTX 280 -- after all, is it really worth 2x the cost [of the 4870] for a card that performs not-so substantially better? Yes the 280 will out perform it but who, I ask of you, would truely take advantage of this performance increase that would not be able to have an enjoyable experience with ATI's counterpart?

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    I was looking forward of reading this review at HH :)

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    great review, just wish overclocking was tested, since according to some reports after an after market cooler, you can get it to be around the gtx 280 level.

    i think its clear that this gen, ati is king. sure nvidia has the better performance but for 2x as much id much rather crossfire the 4870

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    This was definatly a good reveiw. Im impressed with both the ATI and the nvidia cards.The implementation of DDR5 is definatly a plus at the same time with me the price point to performance ratio is probably going to have a factor in my decision when I get in a financial situation to do so.It already has got me excited thinking about an aftermarket cooler just to see what kind of numbers I can acheive in lowering the temps and OCing options. When I get ready to pick up one of these Bad Boys they,ll be more updates to this reveiw by HH.Good read HH!

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    What I thought was most significant is that two 4850's in Crossfire performs almost identically to a single GeForce GTX 280 in all tests, but the dual 4850 setup ends up being around $250 cheaper (2x$199 vs $649). That is a huge deal. Even considering potential Crossfire scaling issues with certain games, you're still clearly ahead with a $250 savings.

    The best part is, since the 4850's are single-slot cards that use a single 6-pin power connector, dual 4850s technically have the same physical footprint as a single GeForce GTX 280. Granted, the Crossfire setup would produce more heat and consume more power than a single GTX 280, but the difference isn't huge. I don't even see the point on a single GTX 280 setup now.

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    LovelyCrap:
    What I thought was most significant is that two 4850's in Crossfire performs almost identically to a single GeForce GTX 280 in all tests, but the dual 4850 setup ends up being around $250 cheaper (2x$199 vs $649). That is a huge deal. Even considering potential Crossfire scaling issues with certain games, you're still clearly ahead with a $250 savings.

    The best part is, since the 4850's are single-slot cards that use a single 6-pin power connector, dual 4850s technically have the same physical footprint as a single GeForce GTX 280. Granted, the Crossfire setup would produce more heat and consume more power than a single GTX 280, but the difference isn't huge. I don't even see the point on a single GTX 280 setup now.
     

     

    Well thats my thinking on it even at a savings of $250 over the 280,s Certainly the option of ati,s single card slot would be in my price range and of course the pricing as it is I think will cause nvidia to be a little more competitive in its pricing!

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    I too am very pleased by the results of this review, but where's my HD video IN? We still need cards that can take in an HD signal with a DVI or HDMI plug. Regardless, I'll probably be buying one of these before long.

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     well ya never know. nvidia may slash the prices on the gtx 280 now to stay in the game otherwise I don't see them selling.

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    I doubt the 280 will be available for under 6 bills for at least a couple months and probably won't be under 5 till next year... just my oppinion.

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