Closer Look: ASUS Radeon HD5870 V2

The ASUS EAH5870 v2 is a good example of how to focus on the basics of technology. The first generation products of any new technology are often over-designed in order to showcase the best parts, hide the bad parts, and ensure reliability. The reference designs for the ATI HD 5870 certainly fit this mold, featuring multiple state-of-the-art power controllers and a cooling assembly that only needed a 40% fan speed to handle the toughest GPU stress tests. The second generation EAH5870 started with a clean sheet of paper, and it really shows. We're going to take a closer look at what ASUS has accomplished here, and some details in the next section.

The first thing you notice with this video card is the oversized fan opening and the bold, red V-shaped accents on the black shroud. It should be obvious to any computer enthusiast today that bigger fans push more air with less noise, all else being equal. Those huge 200mm case fans really do work; it's not just an image thing. It's also a given that increasing clock speed and voltage for any GPU will increase heat generation within the chip, which has to be removed. So, if you're going to release a graphics card that is just begging to be overvolted and overclocked, it's a wise idea to bump up the cooling capacity, as well. The fan upgrade is an obvious enhancement, but ASUS didn't stop there; there's a surprise waiting under the shroud, as we'll see later.

The build quality of the ASUS card is very good. The heatsink-fan assembly is well thought out and executed perfectly. The cast aluminum frame that ties everything together is a complex part that is expensive to produce, and it provides a very stable mechanical structure for the entire card. Even if you press hard enough on the shroud to bend the outside shell, the metal skeleton inside keeps the PCB free from stress. Subjectively, you can feel the difference in rigidity with this card; it doesn't twist or bend at all.

In addition to the cooling changes, the ASUS EAH5870 v2 incorporates significant changes to the power supply, compared to the reference cards. The new design provides the muscle of the original HD 5870, but with a much simpler system of software voltage control and more conventional choices for the individual power components. The overall size of the card has been reduced, it's shorter by about half an inch, and this was achieved primarily by simplifying the power supply section. In contrast to a few other vendors, ASUS has not adopted DrMOS (Driver-MOSFET) VRM chips, which integrate three discrete power devices into a single chip and occupy half the space. We'll look at the VRM section in detail later, including the controller chip as well as the discrete power chips.

The PC board had excellent solder quality and precise component placement, as can be seen here. The component placement is quite good; this is the area on the back side of the board, directly below the GPU, and is one of the most crowded sections of the board. I've included a standard sewing pin in the photo below to show a sense of scale; the littlest components are just specks when viewed with the naked eye. By my estimate, it looks like you could fit two or three of those resistors on the head of a pin. This is one of the most critical sections of the PCB for build quality, as variations in stray capacitance here could impact the performance of the GPU, and certainly its overclocking ability.

I wasn't impressed by the amount of stray fibers stuck to the surface of the board. They're probably remnants of a brush that is used in the cleaning process, after the wave soldering step. I also saw some residue between components, which should have been removed by the same cleaning process. Manufacturers are under pressure to minimize the environmental impact of their operations, and cleaning processes have historically produced some of the most toxic industrial waste streams. The combination of eco-friendly solvents, lead-free solder, and smaller SMD components have made cleaning a lot more difficult than it used to be. Everyone in the idustry struggles with this, as it's hard to find a balance between cost, effectiveness, and ecological impact. As the old saying goes, "I can give you two out of three, no more."

The layout on the front and back of the printed circuit board is standard for a card in this class. Due to the simpler design, there are fewer components mounted on the back side than on a 5870 reference card, but the front side is just as crowded. The GPU cooler is mounted with four spring-loaded screws, and the help of a skeleton back plate. The black PCB was clean and shiny, with very little residue, aside from those brush fibers, and there was no visible evidence of rework.

The board is fed from two PCI-E power connectors exiting the rear of the card, breaking with the original reference design by replacing one of the 6-pin connections with an 8-pin. ASUS is not the first vendor to do this, but many have questioned the effectiveness of the move. The 6-pin PCI-E connection is highly underrated, at 75W each. Since the 8-pin connection is rated for 150W, I don't understand how 33% more pins give 100% more power. And BTW, the extra two pins are both for ground; there are still only three 12V+ pins, so it's really like 0% more pins providing 100% more power. The real capacity of a 6-pin connector is at least 100W, so there is at least 275 W available from the standard connector arrangement, well above the card's 188W maximum requirement.

What we're seeing is a design that makes use of the knowledge gained from six months of experience in the marketplace with the reference design. There isn't as much of a shift away from the basic elements of the reference design as we've seen with some other vendors. The changes are more evolutionary; a refining of the design rather than a redefining. We'll examine the impact of these design decisions in our testing section. For now, though, let's look at some of the components of the ASUS EAH5870 v2 in more detail.

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