|Diamond Viper ATI Radeon HD 3870 512MB Video Card|
|Reviews - Featured Reviews: Video Cards|
|Written by Ronald Tibbetts|
|Tuesday, 11 March 2008|
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Diamond HD 3870: Closer Look
Based on the reference design by ATI/AMD the Diamond HD 3870 comes in at 9 inches (22.86cm) in length. Though still a long card, by comparison it's a half an inch shorter than its predecessor the HD2900XT. The only distinguishing visual features that set the Diamond HD 3870 apart from its add-in board peers is the lack of any art stickers on the cooling fan shroud, and the placement of a Diamond logo on the fan. The translucent red acrylic fan shroud gives the card a hot rod look that is sure to please many, and fits right in with the rest of the cards motif of red and black. Common with most reference designs, the construction is top-notch, and though it's likely not going to beat an aftermarket cooling solution the stock cooler needs no set-up, and has the added bonus of reduced mechanical failure and warranty coverage.
The Diamond HD 3870 does away with the dual power adapter scheme of 6-pin and 8-pin plugs, a result of the reduction in power draw due to the die shrink. With the reduced draw the Diamond HD 3870 only requires one 6-pin power plug to feed its 105W peak draw. The power adapter is also conveniently placed along the top edge of the card orientated towards the front of the card; making cable management much easier.
Perhaps one of the most requested features from enthusiasts is to have video card heatsink fans exhaust the hot air from the card out of the case through the expansion slot, as opposed to depending on good air-flow inside the case for exhaust. It seems as though someone at ATI/AMD was listening when they designed the cooling for the HD 3870. Even conscious of the possibility that the vent may be blocked they have designed additional vent holes in the fan shroud to allow warm air to escape despite any obstruction. The cooling solution on the Diamond HD 3870 will take up an additional expansion slot.
Regarding the noise levels of the cooling fan; despite best efforts to drive the card into kicking in the fan at higher speeds it never did, remaining at a constant 30%. With temperatures leveling out at 63c at 100% GPU load with an ambient temp of 21c. At this temperature the fans noise levels were hardly audible over ambient levels. To test at what percentage of fan speed noise levels were audible we used RivaTuner to simulate levels the card would not under normal circumstances use. In our findings at a level of 60% of full speed the cooling fan was clearly audible over ambient noise though still acceptable, with anything over 75% resembling the noise levels of a small vacuum cleaner.
The heatsink fan assembly is the best stock cooling solutions we have seen in awhile on any video card. Utilizing a simplistic design of an all copper baseplate and heatsink with extruded fins, the fins that have a slight curve to help disrupt air flowing over them, thus maximize heat transfer. the fan shroud is made of a sturdy semi-transparent acrylic plastic (red of course) that is held in place with only four spring retention screws, making removal a cinch for those wanting an aftermarket cooling solution.
In addition to the HSF for the GPU, the memory also gets its own heatsink treatment that is separate from the GPU's. This is perhaps the only disappointing aspect of the cooling solution used on the HD 3870 reference design. For reasons unknown to us ATI/AMD chose to use a raised non-contact heat spreader for the memory modules that does not directly touch the memory. Instead, there is thermal foam to create contact between the heat spreader and the memory. There is no way of using the stock heat spreader without thermal pads as ATI/AMD has seen it necessary to make it so the heat spreader is raised above the memory by its very screw mounts. The cooling for the voltage regulators is without this flaw and though it still makes use of thermal foam pads, the heat spreader can and does make direct contact.
The vRAM and GPU of the Diamond HD 3870 utilize the same basic layout as the previous generation with the exception of the mounting bracket around the GPU. Here is also seen the dual CrossFire connectors implemented, that until the release of CrossFireX was of no use on Intel chipsets - only one connection being necessary for standard two card set-up. With the release of Catalyst v8.3 there comes CrossFireX support that enables any HD 3800 based video card to be paired with another to take advantage of the dual connectors.