Sapphire Radeon HD 3870 Atomic

The second RV670 card we’re looking at today is Sapphire’s 3870 Atomic. Like the 3850 Ultimate Edition, the Atomic’s most distinguishing feature is its cooling, but while the Ultimate Edition runs at the stock Radeon 3850 clock speeds, the Atomic board is overclocked from the factory for additional performance. First we’ll discuss the board’s cooling though.


If you recall our Radeon HD 3870/3850 Performance Preview article, you’ll remember that we discussed the possibility of single-slot Radeon HD 3870 cards. As you can clearly see, Sapphire’s 3870 Atomic is one such board. How does Sapphire accomplish this? Vapor chamber technology.

Sapphire’s Vapor chamber technology works much like a conventional heat pipe. The following chart diagrams the various components within the vapor chamber cooler:


As you can see, the cooler is a sealed vacuum chamber composed of various “wicks”. There’s a vaporization wick, condensation wick, and a transportation wick. Heat from the GPU heats up the liquid (pure water) within the vaporization wick, causing it to vaporize. This water vapor then moves through the vacuum until it hits the condensation wick. Here the water vapor condenses and forms back into a liquid (releasing the heat in the process); this liquid is then absorbed by the transportation wick (by capillary action), where it’s then transported back to the vaporization wick and the process is repeated.

So what makes vapor chamber technology superior to heatpipes? According to Sapphire, vapor chamber is more effective, as its omni-directional versus the uni-directional nature of heatpipes. Sapphire also claims that their vapor chamber cooler boasts 50% lower thermal resistance than copper, with higher heat conductivity as well.



But how does it perform? In our testing, the Sapphire vapor-x cooler outperformed the stock Radeon 3870 cooler, while generating very little noise as well. Also keep in mind that the Sapphire cooler was able to accomplish this while the card was running at higher clocks…

Higher clock speeds

Rather than relying on the stock Radeon HD 3870 clock speeds, Sapphire has chosen to overclock the 3870 Atomic. The GPU is clocked at 825MHz, which is 50MHz higher than the stock 3870 speeds, while the board’s memory runs at 1200MHz (2.4GHz effective), an improvement of 75MHz over the stock AMD specifications.

Bundle and accessories

Sapphire really went out of their way with the Atomic bundle and packaging. You see, rather than relying on a traditional cardboard box for the card’s packaging, Sapphire houses the card inside a small metal briefcase! Once you pop open the case, you’ll be greeted to the Atomic card itself, as well as a promotional brochure listing the card’s specs. Lying underneath the card you’ll find even more goodies including a voucher for Valve’s Orange Box, which includes Team Fortress 2, Portal, and HL2: Episode Two, a copy of 3DMark 06 Pro, Cyberlink PowerDVD and DVD Suite.

Hardware accessories bundled with the card include the usual accessories: six-pin PCI Express power adapter, S-Video cable, CrossFire connector, component video cable, a DVI to VGA adapter, and an HDMI to VGA adapter, as well as two accessories you don’t normally find with a graphics card: an HDMI cable (!), and a cold cathode case light!