ATI Radeon HD4870X2

The double-teamed graphics card that proves fast things can come in a relatively small package

AMD moved its entire product line to a 55nm production process with its 3-series series cards, but their performance was always below what NVIDIA could offer. No longer. Codenamed the RV770 (incidentally the same core that was reviewed in issue 92), this core has an insane 956 Million transistors, which is actually less than the competition with 1400 million.

The small manufacturing process means a very large amount of cores can be produced on a single silicon wafer, which in turn leads to lower costs to manufacture, and therefore less cost for us. It also means that less heat will be produced, and allows higher clock speeds. The choice to include GDDR5 support with this new core is a great idea too, as the memory bandwidth is a significant improvement on the current NVIDIA mainstay of GDDR3.

So what do you do when you have a single fast core that is already the equal for the value performance crown? AMD thought to slap two of them on the one card.

The two RV770 cores are joined together on a single PCB, measuring a massive 28.5cm and weighing just over a kilogram. A PCIe bridge chip lies between these two cores, and emulates the PCIe express bus of the motherboard, allowing very high bandwidth communication. Each core has exclusive access to 1GB of GDDR5, which is more than enough for extremely large resolutions with large textures.

Another thing that these cores share is the cooler. This is a reference design, and comprises of two 400 gram solid copper heatsinks on each core, cooled by a large ‘squirrel cage’ fan. The memory is cooled on one side by this heatsink, but also cooled on the rear of the card by a large black plate. While this seems excessive, it’s because there is an insane amount of heat to deal with. Idle temperatures were not too bad, with 56 degrees at 52.2dBA. Load temperatures shot through the bloody roof, however, hitting a max of 83 degrees with the cooler screaming along at 70.6dBA.

Performance of the two cores is extremely good, pulling in great scores in both 3DMarks and CoH. The 4870X2 was even able to sustain good frames while running at 1920 x 1200 with 8xAA and 16AF, all at stock.



Naturally we couldn’t be content with only two graphics cores, so we did the only thing that we could do in this situation – get two more cores. With two cards and four cores in CrossfireX, we actually found that 3DMark06 decreased. This is due to an extreme CPU bottleneck, but is negated by the performance increase noted in Vantage, which is more GPU-based. Good performance with high amounts of AA/AF was also found with this setup.

One of the unfortunate drawbacks of such a hot card is that when you get two of them in close proximity to each other, the issue becomes compounded. Temperatures under load were 84, but idle skyrocketed to 69 degrees. This is the temperature that most cards run at under load.

We even crashed the system at stock speeds, using 3DMark Vantage at the highest resolution and AA – hitting a max temp of 91 degrees before giving up and freezing.

This is a blisteringly fast card. It runs hot, but is perfect for anyone who needs the fastest card possible at a very good price.