Exactly one week ago today, AMD unleashed the ultra powerful, DirectX 11-ready ATI Radeon HD 5870 upon the PC gaming world and staked a claim as the undisputed 3D performance leader. Having evaluated the features, performance, and image quality of AMD's latest and greatest flagship we were left thoroughly impressed, not only with the new Radeon's killer performance, but its extensive feature set, excellent image quality, power consumption, and competitive price.
In our coverage of the official launch of the Radeon HD 5870, we also revealed AMD's plan to release a more affordable, pared-down version of the card, with a shorter PCB, lower core and memory frequencies, also sans a few stream processors and texture units, dubbed the Radeon HD 5850. Unfortunately, cards did not arrive in time to be tested alongside the 5870. The Radeon HD 5850 did arrive in the lab a few days later, however, and we jumped right on testing it.
We've got our evaluation of the $259 Radeon HD 5850 available on the proceeding pages. First up some specs and a quick refresher, then its onto the close ups, performance, and a little overclocking... 

AMD Radeon HD 5850 DirectX 11 Graphics Card
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| AMD ATI Radeon HD 5850 |  
| Specifications and Features |  | 
| 2.15 billion 40nm transistors 
 TeraScale 2 Unified Processing Architecture
 
 
GDDR5 Memory Interface1440 Stream Processing Units 
72 Texture Units 
128 Z/Stencil ROP Units 
32 Color ROP Units 
 Up To 128GB/sec of memory bandwidth
 
 PCI Express 2.1 x16 bus interface
 
 DirectX 11 support
 
 
OpenGL 3.2 supportShader Model 5.0 
DirectCompute 11 
Programmable hardware tessellation unit 
Accelerated multi-threading 
HDR texture compression 
Order-independent transparency 
 Image quality enhancement technology
 
 
ATI EyefinityUp to 24x multi-sample anti-aliasing 
Super-sample anti-aliasing modes 
Adaptive anti-aliasing 
16x angle independent anisotropic texture filtering 
128-bit floating point HDR rendering 
 
Advanced multi-display technology 
Three independent display controllers 
Drive three displays simultaneously with independent resolutions, refresh rates, color controls, and video overlaysDisplay grouping 
Combine multiple displays to behave like a single large display ATI Stream acceleration technology 
OpenCL 1.0 compliant 
DirectCompute 11 
Double precision floating point processing support 
Accelerated video encoding, transcoding, and upscaling 
Native support for common video encoding instructions ATI CrossFireX multi-GPU technology 
Dual, triple, and quad GPU scaling 
Dual-channel bridge interconnect   | ATI Avivo HD Video & Display technology 
UVD 2 dedicated video playback accelerator 
Advanced post-processing and scaling 
Dynamic contrast enhancement and color correction 
Brighter whites processing (blue stretch) 
Independent video gamma control 
Dynamic video range control 
Support for H.264, VC-1, and MPEG-2 
Dual-stream 1080p playback support 
DXVA 1.0 & 2.0 support 
Integrated dual-link DVI output with HDCP 
Max resolution: 2560x1600Integrated DisplayPort output 
Max resolution: 2560x1600Integrated HDMI 1.3 output with Deep Color, xvYCC wide gamut support, and high bit-rate audio 
Max resolution: 1920x1200 
Integrated VGA output 
Max resolution: 2048x1536 
3D stereoscopic display/glasses support 
Integrated HD audio controller 
Output protected high bit rate 7.1 channel surround sound over HDMI with no additional cables required 
Supports AC-3, AAC, Dolby TrueHD and DTS Master Audio formats ATI PowerPlay power management technology 
Dynamic power management with low power idle state 
Ultra-low power state support for multi-GPU configurations Certified drivers for Windows 7, Vista, and XP
 Speeds & Feeds
 
Engine clock speed: 725 MHz 
Processing power (single precision): 2.09 TeraFLOPS 
Processing power (double precision): 418 GigaFLOPS 
Polygon throughput: 725M polygons/sec 
Data fetch rate (32-bit): 209 billion fetches/sec 
Texel fill rate (bilinear filtered): 52.2 Gigatexels/sec 
Pixel fill rate: 23.2 Gigapixels/sec 
Anti-aliased pixel fill rate: 92.8 Gigasamples/sec 
Memory clock speed: 1 GHz 
Memory data rate: 4 Gbps 
Memory bandwidth: 128 GB/sec 
Maximum board power: 151 Watts 
Idle board power: 27 Watts   | 

Radeon HD 5850 Feature Summary
The Radeon HD 5850 shares the exact same features as the more powerful Radeon HD 5870. In fact, the GPU powering the card is essentially the same chip with a few functional blocks disabled. Radeon HD 5850 cards are still DirectX 11-ready, support ATI Eyefinity multi-display technology, offer the same UVD updates, and new anti-aliasing and anisotropic filtering modes.
Where the two cards differ are in their allotment of stream processors--the Radeon HD 5850 has 1440 versus 1600 on the 5870. The Radeon HD 5850 also has fewer texture units, a shorter PCB, and a lower clocked GPU and memory. The changes made to the 5850 result in a much lower-power, more affordable product. How much performance has changed remains to be seen, so let's get a move on, shall we?