We like a good combo here at HotHardware, and we have a new one to add to the list. Right up there with peanut butter and jelly, Mario and Luigi, milk and cookies, we'd like to add dual GPUs and factory overclocks. If you are a regular reader, you probably already know we are fans of dual GPU video cards, and we have a strong affinity for factory overclocked video cards as well. And when a company combines the two, that's just fine in our book.
So, it goes without saying that we were excited to check out Diamond's overclocked Radeon HD 4870 X2 XOC graphics card (model number: 4870X2PE52GXOC). As you probably already know, the Radeon HD 4870 X2 employs two RV770 GPUs, each of which is complemented by 1GB of GDDR5 memory (for a total of 2GB frame buffer memory). The reference GPU clock speed for the 4870 X2 is 750 MHz, and the reference memory speed is 900 MHz. We are happy to report that Diamond boosted the XOC's clocks to 800 MHz and 950 MHz, respectively, making this one of the fastest 4870 X2 cards we've seen in the HotHardware labs. Speaking of the labs, we took the XOC for a spin with our benchmark suite and pitted it against a reference 4870 X2, an NVIDIA GeForce GTX 285, an NVIDIA GeForce GTX 295, and a pair of GeForce GTX 285s in SLI. Read on to see how the XOC fared in the comparison.
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AMD ATI Radeon HD 4800 Series |
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Specifications and Features | |
- 956 million transistors on 55nm fabrication process
- PCI Express 2.0 x16 bus interface
- 256-bit GDDR3/GDDR5 memory interface
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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
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Unified Superscalar Shader Architecture
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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
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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
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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
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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
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ATI Avivo HD Video and Display Platform
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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)
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Hardware MPEG-1, and DivX video decode acceleration
- Motion compensation and IDCT
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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
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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
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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)
- Each includes a dual-link HDCP encoder with on-chip key storage for high resolution playback of protected content4
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Two integrated 400MHz 30-bit RAMDACs
- Each supports analog displays connected by VGA at all resolutions up to 2048x15363
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DisplayPort output support
- Supports 24- and 30-bit displays at all resolutions up to 2560x16003
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HDMI output support
- Supports all display resolutions up to 1920x1080
- 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
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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
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ATI CrossFireX Multi-GPU Technology
- Scale up rendering performance and image quality with two GPUs
- Integrated compositing engine
- High performance dual channel bridge interconnect
Since we've covered the 4870 X2 and the powerful RV770 GPU several other times here at HotHardware in various articles, we won't repeat ourselves again here. Instead, we'll invite you to check out a couple of our articles if you want to learn about the technology behind the 4870 X2 and the RV770.
In the first article, where we discuss the launch of the Radeon HD 4850 and 4870, we go into depth on the RV770 GPU's architecture and technology. In the second article, we explain the technology that ATI used to couple two RV770 GPUs on one 4870 X2 card. |
