|PowerColor PCS+ HD6950 Vortex II|
|Reviews - Featured Reviews: Video Cards|
|Written by David Ramsey|
|Sunday, 22 May 2011|
Page 5 of 17
HD6950 to HD6970: Unlocking Extra Shaders
When the Radeon HD6950 cards were introduced, it didn't take enthusiasts long to figure out that they used the exact same GPU as the HD6970, only with some of the shaders disabled. While an HD6970 has 1536 shaders, the HD6950 has only 1408. By re-flashing the BIOS on a 6950 with the BIOS from a 6970, or using a tool such as TechPowerUp's "Radeon BIOS Editor", enthusiasts could enable the unused shaders and gain some performance. Most 6950 cards made it really easy with this little switch:
In the position shown, the card uses its standard, non-modifiable BIOS; moving it to the other position selects a second, modifiable BIOS. This removed worries about "bricking" a card with a failed BIOS update since you can always simply flip the switch to the original position and reboot.
However, I wasn't able to unlock the extra shaders on this card. I tried flashing with several 6970 BIOSes as well as modifying the original BIOS with TechPowerUp's "Radeon BIOS Editor" utility. I could change parameters in the BIOS such as the default GPU and memory clocks, and confirm the changes with GPU-Z, but shader unlocking never worked. I suspect PowerColor (or perhaps AMD) has locked this ability out. PowerColor does offer a 6950-based card, the AX6950 PCS++, which comes with a 1536-shader enabled BIOS pre-installed on the card and accessible via the switch, but that card comes with 8-pin and 6-pin power connectors to handle the extra load, whereas the Vortex II Edition uses two 6-pin connectors. Benchmark Reviews examined the AX6950 PCS++ card here.
Let's see how this card performs just as a 6950.