Asus DirectCU and DirectCU II for AMD: 6850, 6870, 6950, and 6970 Boards Under the Microscope

EAH6950 DCII/2DI4S/2GD5

Now we are heading into the big guns territory.  The AMD HD 6950 is the junior member of the Cayman family.  This VLIW4 architecture is a step up in efficiency from AMD’s previous VLIW5 setup that powers the 6800 series (and the 5000 series before that).  Essentially AMD discovered through testing that the 5th stream unit was under utilized in most DirectX 10 and 11 applications.  By rearranging things and creating this VLIW4 architecture, AMD was able to make the GPU much more efficient per clock.  AMD was also able to increase geometry performance which has a positive impact on tessellation.  Even though this chip uses the same 40 nm process from TSMC, AMD was able to get a huge boost in overall performance with this redesign.

The higher the model numbers go, the less of a bundle there is!  The extra long CrossFire cable is a nice addition though.

The HD 6950 is a partially disabled chip with 1408 stream processors, 32 ROPS, and 88 texture units.  This GPU is fed by a 256 bit memory bus running at 1250 MHz (5 GHz effective) giving a total bandwidth of 160 GB/sec.  The GPU on this particular card runs at 810 MHz, which is again 10 MHz faster than the reference speed for the HD 6950.  The board is powered by 6 pin and 8 pin PCI-E power connections.  This should give the board around 250 watts to play with.

The board design is obviously not reference and Asus has added their own unique touches.  The board supports the Super Alloy Power components, but it does not include the Proadlyzer chip that some of the higher end products sport.

Remember back when the Eyefinity Edition cards came out and were $500 a pop?  Asus has the same functionality but at a much lower price point.

The heatsink and fan combination are beefy, to say the least.  Two 80 mm fans push air through the 2.5 slot wide heatsinks.  The heatsink is actually a two piece unit with three heatpipes going from one heatsink (and GPU) to an array of aluminum fins.  The primary heatsink is a solid, finned unit made of aluminum which helps to direct airflow through the vented portion of the output plate.  The secondary heatsink allows air to pass through it and cool the power circuitry directly under it.  The entire heatsink is covered by the matte black shroud with the red racing stripes.

The biggest surprise of this design is the output connections.  This board has four Display Port connections and two DVI outputs.  One of the DVI ports is dual-link capable, but only if a toggle on the board itself is set to the correct position.  If that port is set to single link, then the Display Port directly underneath that DVI port is activated.  This allows the user to power six 1920×1200 monitors off of this one card (4 DP and 2 DVI).  So far this is pretty unique in the HD 6950 world.  I was at first scratching my head when testing this card as to why the DVI output was limited to 1920×1200 instead of the 2560×1600 that my monitor supported.  Once I actually read the descriptions of the card then I figured out that I had the toggle set to single link DVI.

This thing is a brick.  Get enough of them together and a user can probably make a nice firepit.

This card does not have the power to run most modern games in 6 screen mode, even when in CrossFire mode.  3 card CrossFire might be able to push it fairly adequately, but it is a stretch.  I personally use 2 x HD 6950s flashed to HD 6970s, and they can push 3 x 1920×1200 screens in most games.  Titles such as Metro 2033 and Battlefield 3 at high and ultra quality levels just require more horsepower than these cards can provide, and this is with three monitors and not six.

This card was never loud throughout testing, and it only became audible once overclocking was enabled.  The two fans are PWM controlled and at idle and heavy loads, they never spun up enough to make them audible at stock speeds.  The card stayed very cool throughout testing.

The back is pretty unexciting.  There is no backplate like what we see with the DirectCU II GTX 500 series, nor is there a Proadlyzer chip providing power to the GPU.

The EAH6950 runs around $289 US online.  This is right around the level of the NVIDIA GTX 560 Ti in most cases, but consider that the 6950 does come with double the memory.