AMD's Radeon HD 6790 Reference Card
The reference Radeon HD 6790 is about 10 ¼ inches long and about 4 ¼ inches tall. At 1 lb. 6 oz., it is the exact size and weight of the reference Radeon HD 6870.
Actually, with two six-pin PCIe power cables on top, it might be more accurate to say that the Radeon HD 6790 reference card is identical to the Radeon HD 6870. This is surprising, since we expected that the Radeon HD 6850 would be a closer match, given a relaxed power requirement. This doesn’t seem to be the case, and AMD's specifications indicate 150 W TDP. That's essentially the same as its Radeon HD 6870 and 23 W more than the 6850.
Of course, manufacturers will go their own route, and the reference design is often ignored. We hope to see Radeon HD 6790 cards with only a single PCIe power cable show up. After all, a 16-lane PCIe slot delivers up to 75 W and a six-pin power connector serves up 75 W as well. In theory, there's no reason to ship these boards with two six-pin connectors. And indeed, just before publication, AMD sent us an email saying, "Though the reference boards we sent out to you may resemble the 6870, the AIB designs will vary greatly from what you’re seeing on our sample boards, including PCB, power connectors, cooler design etc. This means the AIBs have the choice to, for example, include one or two power connectors on the PCB." As an example, PowerColor's Radeon HD 6790 will require a single power connector.
Like the Radeon HD 6800-series cards, AMD's Radeon HD 6790 has a single CrossFire bridge, limiting this board to dual-GPU configurations.
The Radeon HD 6790 reference card plays host to two DVI, one HDMI, and two mini-DisplayPort outputs. As with all Radeon 6000-series cards, the DVI port beside the exhaust grille is a single-link output, while the other is dual-link-capable.
The PCB is identical to the Radeon HD 6870; no surprises here.