Board Analysis

Radeon HD 6800 series reference design

At first glance, the 6850 and 6870 look almost identical. In fact, they have the same dual-slot cooling enclosure design, which is decidedly more rectangular than that seen on the HD 5000 series boards, but with a similar style of turbine fan. Oddly enough, the 6870 is almost entirely enclosed, while the 6850 has slots all along the side and rear of the cooler. Both setups do a sufficient job of keeping the GPUs cool, but it appears the 6850’s fan is less powerful than the one on the 6870, since it idles a good 10 degrees warmer:

Sample Temperatures
Radeon HD 6800 Series
	Idle Temp.	Load Temp.
6870 Stock	30° C	66° C
6870 OC	32° C	68° C
6850 Stock	42° C	70° C
6850 OC	42° C	71° C

Upon closer inspection, you’ll find that there is a discrepancy in board length of about 3/4 of an inch. With the 6850 measuring in at exactly 9”, this means the 6870 is closer to 10”. Compared to the 5870 and 5850 (11” and 9.5”, respectively), that doesn’t sound so bad. However, the 6870 still dwarfs the GTX 460, which is just less than 8.5” long.

Both the board length and cooling method of the two speak volumes about each company’s design philosophy when it came to creating these midrange products -- Comparing the two graphics cards side by side, it quickly becomes apparent that the GTX 460 was crafted from the ground up for this application, while the 6870 was modified from the power-hungry, high end GPU of yesteryear.

Another thing that’s changed since last year, sadly, is the removal of the ATI brand name. As can be plainly seen on the fan labels, the transition to “AMD Radeon Graphics” has officially been made. As an enthusiast, it’s easy to decry the decision to ditch the beloved moniker, but you can’t blame AMD for wanting to unify all of their products under a single name. This will become especially important when they come out with the CPU/GPU hybrid chip, Fusion, in the near future.

The 6870 has two 6-pin PCI-E power connectors on the side, while the 6850 has a single 6-pin connector on its end. Both have the same 5 display outputs: two DVI, one HDMI, and two mini DisplayPort connectors. Using a combination of these, a single graphics card can support up to 6 displays simultaneously using AMD Eyefinity. Of course, you can also have 2-way Crossfire, which we have included in our testing. Without further ado, turn the page and move on to the juicy bits!