Board analysis

You’re probably wondering how Sapphire managed to bring their Vapor-X board to market weeks ahead of other ATI board partners who are busy working on their own 2nd-generation 5870 cards.

Part of the reason why Sapphire is able to move so quickly is they have a built-in natural advantage.

You see, like previous high-end graphics card launches, right now ATI is limiting all 5870 board production to a single source: Sapphire’s parent company, PC Partner. All the 5870 board partners receive finished cards manufactured in essence by Sapphire. All they then turn around and do is slap their sticker on the heatsink/fan assembly, throw everything in a box with their own custom packaging+software bundle, and that’s about it.


With Sapphire producing all the boards, they’ve had more time to test and fine tune their custom solution, as they got early access to the final board design.

The other reason why they’re able to bring the Vapor-X to market so quickly is because they’ve made no changes to ATI’s reference board design. Sapphire uses the exact same board level components and power circuitry as the ATI reference board. If you recall, the reference board utilizes 4-phase VRM dedicated to the GPU, and an additional 2-phases for the GDDR5 memory subsystem. Sapphire uses the same Samsung K4G10325FE-HC04 GDDR5 memory modules on the Vapor-X as well. These modules are rated to run at speeds as high as 5Gbps (1250MHz).

Where Sapphire’s 5870 Vapor-X sets itself apart from the other Radeon 5870 boards is its cooling unit. As a Vapor-X board, the card uses vapor chamber cooling technology, which is actually made by a Taiwanese company named Microloops.

Vapor chamber cooling is based on many of the same basic principles as heatpipes, only wicks are used to shuffle heat from the GPU. The vapor chamber is a sealed vacuum chamber that is composed of three “wicks”. There’s a vaporization wick, condensation wick, and a transportation wick.

Heat from the GPU heats up the 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.



The key advantage of the vapor chamber technique over heatpipes is that heat transmission is two directional and planar, while heatpipes are limited to one linear direction. Microloops vapor chamber coolers can be made to fit any shape, and are just 3.0mm thick. In other words, they’re small and flexible enough that you can use them in a wide variety of applications.

In Sapphire’s case, the vapor chamber cooler is housed inside a copper base plate, which rests directly above the RV870 GPU. Heat is pulled off the GPU by the copper vapor chamber, where it’s dispersed.

It doesn’t stop there though. In addition to the vapor chamber itself, Sapphire also uses three large heatpipes to provide additional cooling. These heatpipes are responsible for transferring heat from the vapor chamber and they’re also made from copper to increase their effectiveness.


This heatpipe+vapor chamber combination can dissipate an enormous amount of heat, and as you can imagine, can get quite hot in the process. As a result, a large, dual-slot aluminum heatsink is used to keep everything cool. By using such a large heatsink, heat is dispersed over a greater area than the heatpipes and vapor chamber can provide.

Supplying fresh, cool air is a 92mm fan. Because of its large size, it’s able to push a considerable amount of air through the cooler without having to crank up the RPMs. As a result, it generates very little noise, even when the card is running under load.

One potential downside to Sapphire’s cooler is that the ducted enclosure isn’t completely enclosed. As you can easily see in the photos, the duct has numerous holes at the top of the cooler, and large gaps are present throughout the duct as well. There’s also a huge opening around the back of the card.

With so many openings present on the board’s cooling, very little air will actually exhaust out the back of your system case. Instead most of the hot air from the graphics card is going right back into your system.

Because it lacks the “Phoenix” enclosure designed by ATI for the 5870 reference board, the Sapphire 5870 Vapor-X is actually slightly shorter than the stock 5870 board. The Sapphire Vapor-X board measures 10.5” long, that’s half an inch shorter than the reference board. You do lose the aluminum plate on the bottom of the card though.


This plate helps to lower PCB temps and also protects the card from ESD and damage during shipping.

Overclocked Speeds

For added performance, Sapphire OCs the graphics core and memory on the 5870 Vapor-X. The GPU runs at 870MHz, 20MHz higher than stock, while the memory is clocked at 1250MHz. That’s 50MHz higher than the reference speed of 1200MHz.

Considering their history with the 4870 and 4890 Vapor-X (which ran at ATI’s stock frequencies), we were pleasantly surprised to hear that the 5870 Vapor-X was OC’ed. And while the OC isn’t extreme, it is better than the stock frequencies the other Radeon 5870 cards on the market rely on.

If history is any indication, Sapphire will likely offer Toxic and Atomic Edition 5870 cards at some point in the future with even higher clocks.

Bundle and accessories

Sapphire includes a better than average bundle with the 5870 Vapor-X. Not only do you get a voucher to download DiRT 2 when it arrives in December, the game also ships with a copy of the WW2 RTS from Eidos, Battlestations Pacific.

In addition to the games, hardware accessories bundled with the card include two PCIe power adapters, CrossFire cable, and a DVI-to-VGA adapter.