AMD Radeon HD 6990 4GB Dual GPU Video Card Review

A Closer Look At The Radeon HD 6990

The Radeon HD 6990 4GB GDDR5 is the first video card looks similar to the Radeon HD 6800 and 6900 series, but you should be able to tell that it is different due to the output connections on the end of the card and the centrally located cooling fan. For the most part, AMD stuck with the red/black color scheme
with the wave motif, as you can see from the picture above. We are dealing with a reference design card that came without any bundle. We asked AMD what bundle consumers can expect with this $699 card and we were told this:

All AMD Radeon HD 6990s ship with an extremely cable-rich package, including 1x mini DisplayPort to SL-DVI passive, 1x mini DisplayPort to SL-DVI active, and 1x mini DisplayPort to HDMI passive adapters (not present by default in other products), enabling 3×1 Eyefinity gaming out of the box with legacy displays. The HDMI adapter also provides HDMI 1.4a compatibility as well for AMD HD3D technology. All of these adapters if purchased separately would be worth over $60. – AMD PR

Right away we noticed that the Radeon HD 6990 is longer than the
Radeon HD 6950 and 6850 video cards. We took the picture above to show you the length
difference between these three popular gaming graphics cards. The AMD
Radeon HD 6850/6870 are 9.5″ long, the Radeon HD 6950/6970 are both
10.5″ in length, but the Radeon HD 6990 is a massive 12″ in length! The PCB is only 11.5″ long, but the backplate and fan shroud extend past the card! This card obviously won’t fit in many compact or OEM cases, so be sure to measure inside you chassis if you want to fit one of these cards inside!

As you can see, the Radeon HD 6990 video card is a dual-slot card with a single squirrel cage type cooling fan right in the middle of the video card between the two GPU cores.

The back of the Radeon HD 6990 is blocked off by the metal plate
shown above, so we can’t see what is going on underneath that plate.
Having a plate like this is nice as it usually helps dissipate heat and
also protects the components on the backside from the card when you set
the card down and install/remove it from the system. As you can see the
AMD Radeon HD 6990 uses a PCI Express slot and this is a PCI Express 2.1
slot.

The AMD Radeon HD 6900 series has what they are calling a ‘Dual BIOS
Toggle Switch’ and this is a pretty neat feature that we need to talk
about. This switch allows you to switch between two totally separate
BIOS versions on the Radeon HD 6900 series graphics card. AMD said that
these boards have two BIOS chips (EEPROM) that both have separate
lanes. If you want to tweak or flash the card to a different BIOS you
can always do so on setting number 1, which is unprotected and for user
updates. Setting number 2 is protected as the factory default and can’t
be flashed by end users.

The switch on the AMD Radeon HD 6990 that was sent to us for review came with an overclocking profile already setup and ready to use on Postion 1. This profile had the core clock at 880MHz and had the voltage cranked up to 1.175V for stability. The settings on Position 2 were what we tested with and were the cards rated clock speeds of 830MHz at 1.12V.

The AMD Radeon HD 6990 uses two 8-pin PCIe power
connectors located
at the along the top corner of the video card. AMD didn’t tell us what
the power supply requirements are, but we do know the card uses more than 375W at max load. We also know that AMD designed this card to work at 450W as it was designed with overclocking from the start.

The AMD Radeon HD 6990 has four mini-DisplayPort 1.2 connectors
on it that have double the data-rate of DisplayPort 1.1. In addition to
the higher data-rate, DP 1.2 also brings support for higher resolution
support and support for stereoscopic 3D. To the right of the mini-DisplayPort connectors is a dual-link DVI-I output.

This means that with the three adapters that comes with every card you’ll be able to setup and run an eyefinity display setup if you wish. Our card didn’t include any cables with it, but you can check out the cables that come with the card in the image above.

The Radeon HD 6990 only has one CrossFire interconnect. This means that you’ll be able to run just another card with it for quad CrossFire down the road.

The Radeon HD 6990 video card has a rather beefy GPU cooler underneath the fan shroud as you can see from the image above.

In this shot of the PCB you can see both of the GPU cores along with the PLX bridge chip that is used to bridge the two chips together. As you can see the is rather full and it really does need to be 11.5″ in length!