Review: Troll switches, begone! Sapphire's HD6950 delivers good 'clocks, and a solid price.
Midrange cards are as attractive as ever. With every generation of GPUs, we're seeing the three main tiers of cards each drop in price. It was only a few years ago that a 7900GT would set you back $500, and you'd be looked down upon by those who sported the fancier 7900GTX, which cost about an arm and a leg (exchange rate for limbs at the time places that at about $800). Midrange these days sets you back half of what it used to, and with the abundance of console ports, the desire for the best models tends to dissipate quickly. The Sapphire HD6950 Dirt3 edition takes a stab at tackling the midrange market with its custom HD6950 design.
Visually, the Dirt3 edition differs with the choice of a dual-fan configuration over the stock squirrel-cage cooler. Five large heatpipes transfer heat from the hot Cayman Pro core to the aluminium heatsink above it. The cooling componentry is covered by a jet black shroud with Sapphire labeling, which is interesting considering the Dirt 3 inspired model name (and probably a good thing, given the corny nature of GPU decals). All in all, this is a quieter and more effective set up over the stock solution.
It just so happens that video card manufacturers decided to remove a little known feature on recent HD 6950 releases. A small switch, about the size of a thin grain of rice, and commonly found in difficult to reach areas of the PCB, allowed users to easily switch between two GPU BIOSs. The removal of this switch meant flashing the BIOS became a risky process on many cards. So why would a manufacturer remove such an innocent sounding feature? To stop people flashing HD6970 BIOSs on their HD6950 cards, and thus attaining extra performance without paying the premium. We're not just talking voltage and clock rate increases, shaders were being unlocked too!
So, you can tell how intrigued we were to see that Sapphire had provided a BIOS switch on the Dirt 3 edition of their HD 6950. We promptly installed the card and got to work looking for a suitable method of flashing the BIOS. It turns out, to our ultimate despair, that the switch is a ruse! This card cannot be successfully flashed to a HD6970. Our glimmer of hope was dashed, but we still had our trusty overclocking tools at hand. Instead of using MSI Afterburner (our usual tool of choice), we installed Sapphire's own tool, TRIXX, hoping that it'd allow greater control over voltage settings. Perhaps it was just a terrible day, but it refused to function correctly, failing to detect the presence of the card. Interestingly, the official webpage to download TRIXX was also broken – oh dear! But that's okay, our trusty copy of Afterburner did the trick, and we were finally in business.
From the stock core clock of 800MHz, we were able to attain a solid 898MHz stable after an hour or so of tweaking, and similarly a boost from 1250MHz to 1310MHz on the memory. The fans were clearly audible over the already chatty office environment, however they didn't have anywhere near the impact of the reference coolers loud whine.
Connectivity includes 2 x DVI-D (one dual-link), HDMI and Displayport 1.2 output. Bundled with the card is a coupon for Dirt 3, a CrossFire bridge, DVI to VGA adapter, 2 x Molex to 6-pin power cable and a 1.8m HDMI 1.4a cable.
When you consider the performance of this card compared to the XFX xXx Edition HD6950 we reviewed earlier in the year, it's clear that this isn't the best performing HD 6950 on the market. It is cheaper though, and we're certain that with a functioning copy of TRIXX, this card could be pushed closer to the 950MHz OC of the XFX card.
Issue: 137 | June, 2012