The smaller card
The Radeon HD 5850 1,024MB has the outward appearance of the HD 5870, dressed in red-and-black livery and sporting intake 'ducts', but it's a tellingly shorter card.
Designed to fit into the majority of systems, the HD 5850 measures 243mm long, 111mm high and 35mm deep. That, then, makes roughly the same size as the Radeon HD 4890 board and around 30mm shorter than the range-topping GPU. It's a little lighter too, tipping the scales at 860g - almost 100g less than you-know-what.
The monstrous HD 5870 is at the top of this comparison shot. Lower clock-speeds intimate less regulation circuitry for the HD 5850, which in turn leads to a smaller, more-cost-efficient PCB and cooler that's otherwise identical in design.
Just like its bigger brother, the HD 5850 is practically silent in 2D and quiet in 3D, making it the most acoustically-preferable high-end GPU around.
The PCB also sports dual CrossFireX fingers that can enable up-to four-board multi-GPU usage.
AMD's reference card modifies the HD 5870 layout by situating the dual six-pin PCIe connectors from the side to the front.
Load power-draw is down by 20 per cent, falling from a maximum of 188W to around 151W. The idle figure of 27W - the lowest of any decent card - is consistent for both 58xx GPUs, and both clock down to 157MHz/300MHz when tasked with 2D work.
Continuing the spot-the-difference game, the rear of the card is left exposed, rather than enveloped in an all-around 'frame'.
The rear of the card is identical to HD 5870. It harnesses a total of four digital outputs that span DVI and sound-carrying DisplayPort and HDMI.
We like the fact that the pass-through audio features bit-stream support for TrueHD and DTS-HD Master Audio, as well as 8-channel LPCM.
Summary
AMD's Radeon HD 5850 1,024MB graphics card is, much like the architecture, a scaled-down version of the HD 5870 1,024MB, We look upon the £200 design favourably because it will fit into most standard chassis without interfering with other components.
