ATI Radeon HD 4850 Single and CrossFire Mode Review
ATI Radeon HD 4850 Single and CrossFire Mode Review PDF Print E-mail
Written by Jeff_Tom   
Sunday, 15 June 2008 11:06
Article Index
ATI Radeon HD 4850 Single and CrossFire Mode Review
Benchmarks, Overclocking
Conclusion
All Pages

 

 

 

 

 

 
After numerous hurdles in getting their 2900 line of cards out, in finally catching up to Nvidia in getting a DX10 card out even if it was one that was too hot and didn't perform well, ATI managed a significant comeback late last year with the 3000 Radeon series of cards especially the 3870X2, 3870, and 3850. Performance increased dramatically able to compete with Nvidia, price, and power consumption. But Nvidia has come back first with the 9800 GTX then the incredibly expensive GTX 280. And what does AMD have to bounce right back but the brand new Radeon HD 4850 launching today and in a few weeks the Radeon HD 48 4870 which should topple the GeForce 9800 GTX.

Below is the shot of the actual card we used from our friends at Visiontek.  We received two cards from the trip to the launch in San Francisco and some other goodies have since arrived in Austin.  Or across town at least.

 

Time is one thing that is not on our side as ATI pushed the NDA expiration ahead a week as cards have already started to flood the channel making the time for the review very tight. We'll cut straight to the chase here and give you the specs. The gist of it is this is a second generation 55nm Radeon product and the 4000 series brings some amazing gains in stream processor count and efficiency.

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 ATI Radeon HD 4850 ATI Radeon HD 3870
Manufacturing Process 55nm 55nm
Stream Processors 800 320
Texture Units 40 16
Render Back-Ends 16 16
Core Clock Speed 625Mhz 775MHz
Memory Data Rate 2.0 Gbps GDDR3 2.25 Gbps GDDR4
Math Processing Rate (multiply-add) 1.0 TeraFLOPS .497 TeraFLOPS
DirectX Support 10.1 10.1

 

The MSRP for the Radeon HD 4850 will be $199.


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 pixels
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 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
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)3
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 2560x1600
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 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 CrossFireX™ Multi-GPU Technology
Scale up rendering performance and image quality with two GPUs
Integrated compositing engine
High performance dual channel bridge interconnect5

 

Our first impression of this card in the limited time we had is that it is amazing ATI put so much power into a single slot card. It does appear to run very hot, at around 155 degrees Fahrenheit by our initial tests but it is a single slot card and we can say the fastest single slot card on the market. A bigger heatsink/fan could have helped but it seems to be quite a powerful package for an amazing price.

 



Last Updated on Saturday, 21 June 2008 19:35