Like ATI's reference Radeon HD 2900 XT, the Diamond Viper HD 2900 XT 1GB features a dual-slot cooling solution that covers almost the entire front side of the card. It's built almost completely from copper and features multiple heat-pipes connected to its base plate and heatsink fins. The cooling unit's barrel fan draws air into the shroud, where it is forced through the heatsink and exhausted from the system through vents in the card's mounting plate.
In a stock configuration, the GPU on the Diamond Viper HD 2900 XT 1GB is clocked at 742MHz and its 1GB of GDDR4 RAM is clocked at 1000MHz (2GHz DDR), please note that a high-clocked version is in the works and is currently shown on the Diamond website. At these frequencies that card has a theoretical peak pixel processing rate of 47.5 Gigapixels/sec and a peak triangle processing rate of 742M triangles/s. It also has up to 128GB/s of memory bandwidth thanks to its 512-bit memory interface, and increase from 106GB/s on reference 512MB cards.
The Diamond Viper HD 2900 XT 1GB cards are outfitted with two supplemental power connectors, one common 6-pin PCI Express connector and one 8-pin PCI Express power connector. The card will function properly with a pair of 6-pin power feeds, but users won't be able to overclock their cards unless an 8-pin feed in connected. This supplemental power connector configuration is necessary because a single Radeon HD 2900 XT can consume upwards of 215 watts.
As you probably expect, the card also has native CrossFire support and doesn't require an external dongle. Updates to ATI's drivers further enhance CrossFire by eliminating the need for application specific profiles. According to ATI, upcoming Catalyst drivers will default to AFR mode to accelerate an application right out of the gate. But the drivers also have a built-in mechanism to detect whether or not an application is AFR compatible, and if it isn't, a different mode will be used.
The Diamond Viper HD 2900 XT 1GB cards are equipped with dual, dual-link DVI outputs with HDCP support and cards outfitted with a Theater 200 chip and feature ViVo functionality as well. And as is the case with other Radeon HD 2000 series cards, these have the ability to output digital audio over HDMI though the use of a special adapter that's included with the cards as well.