When the first screenshots of what was supposedly a Radeon HD 5970 surfaced on the Internet, we were slightly shocked to read that the card was a whopping 13.5 inches long. This meant that only the largest of casings would be able to accommodate it.
And our fears came to fruition when we finally unpacked the HIS Radeon HD 5970. At 12 inches long, it was shorter than we had first feared, but still long enough to pose a problem for most users with medium-sized casings. It just about made it into our Cooler Master Storm Sniper, and that's already a huge casing.
Despite the added length, the Radeon HD 5970 retains a similar cooler design to the one on the other Radeon HD 5000 series cards - at least from the exterior outlook. This means it gets a single fan, and two vents at the opposite end of the connector ports. With the card being so long, this also means that the fan is now situated further away from the GPU cores, and we can't help but wonder if this will have a negative effect on operating temperatures. Fortunately this wasn't the case in our temperature testing segment. Internally, we were told that it it's a vapor-chamber based heatsink to accelerate heat draw and massive heatsinks akin to the previous "X2" series of dual-GPU graphics cards.
Perhaps that is why the Radeon HD 5970 card's clock speeds are on the conservative side to ensure the cooler can handle the job decently. Remember, a single Radeon HD 5870 is clocked 850MHz at the core and 4800MHz DDR at the memory. The Radeon HD 5970, however, is only clocked 725MHz at the core and 4000MHz DDR at the memory - equivalent to the Radeon HD 5850 clock speeds, but retains all the processing units available on the Cypress XT GPU. If you're watching the numbers, the new Radeon HD 5970 won't displace the CrossFire pair of Radeon HD 5870 graphics cards yet as you'll soon see.