It has been a few months since the AMD Radeon HD 6990 initially launched. Since that time, a number of AMD’s board partners have launched their own Radeon HD 6990 cards, but as is typically the case with the first wave of products based on a new GPU, they all conform to AMD’s reference design, save for a water-cooled card from PowerColor.
While most of the Radeon HD 6990 cards on the market today are fundamentally very similar, we thought it would be a good idea to check out a retail-ready 6990 using AMD’s latest drivers to see how well the card performs (and behaves) with updated software. To that end, we got our hands on an HIS Radeon HD 6990 card and have put it up against NVIDIA’s best to see how things sake out in a handful of games and applications.
We’re not going to rehash all of the low-level technical details regarding the Radeon HD 6990 in this article, however. If you’d like a refresher on the Radeon HD 6990’s inner working, we’d suggest taking a look at our launch coverage here. Checking our coverage of the AMD Cayman GPU would also be a good idea; those details can be found in our Radeon HD 6900 Series coverage here.
In its default, non-overclocked configuration, the HIS Radeon HD 6990 has an 830MHz GPU frequency (@1.12v), with 1,250MHz memory (5.0Gbps effective data rate). There is 4GB of on-board frame buffer memory—2GB per GPU. There are a total of 3072 stream processors enabled across both GPUs, with 192 texture units, and 64 ROPs. If you add all of this up, what it amounts to is roughly 2x of everything available on a reference Radeon HD 6970, save for the GPU clock (reference Radeon HD 6970 cards are clocked at 880MHz).
Having two high-end GPUs and 4GB of memory on-board obviously requires plenty of power to operate, so two supplemental 8-pin PCI Express power connectors are necessary with the HIS Radeon HD 6990. Typical load board power can approach 375 watts, which is the maximum rating for a board with this power connector configuration (150 watts per 8-pin feed plus 75 watts from the PEG slot). As is the case with reference Radeon HD 6990 cards though, with the flip of a switch, the HIS Radeon HD 6990 can be run in an overclocked “AUSUM” mode that pushes the GPU clock to 880MHz (@1.175). With the GPUs running at the higher clock and voltage, board power can exceed 415 watts, which also exceeds the power specifications, so using this mode is going to require a potent PSU. AMD’s Powertune technology with is integrated into the card’s drivers is configured to not exceed 375 watts when the 6990 is running in its stock configuration, but that number is upped to 450 watts when overclocked.
The Radeon HD 6990 is a full 12” long and the entire card is encased in a fan shroud on the front and a heavy duty metal heat-spreader on the back. A barrel-type cooling fan, common on all recent Radeons resides smack-dab in the middle of the card, which forces air across two heatsinks on either side, which are affixed to the pair of GPUs. Some of the heated air is expelled from the system through vents in the card’s mounting bracket, while the rest is exhausted out of the back of the card and into the system. In addition to making sure a system has the room to fit a beast like this, good case cooling is also a must.
The output configuration on the HIS Radeon HD 6990 consists of four mini-DisplayPort connectors and single dual-link DVI port. This card supports AMD’s Eyefinity multi-display display technology and can drive up to five displays simultaneously.
In terms of HIS specific tweaks to the card, a few custom decals affixed to the fan shroud and fan are it. The bundle is also pretty standard and includes a CrossFire Bridge, 2 x Power adapter cables, an Active Mini Display Port to Single-Link DVI dongle, a Passive Mini Display Port to Single-Link DVI dongle, a Mini Display Port to HDMI dongle, a Mini Display Port to Display Port dongle, a DVI-VGA Adapter, a Install CD, Quick Installation Guide, and an “HIS Power Up” case badge.