AMD'S ATI Radeon HD 3870 X2 marks first real dual-GPU supported and manufactured by AMD.

Previous attempts were mostly made by third party manufacturers such as ASUS, Sapphire and MSI, but this time AMD is coming into the frame.

With R700 looking quite interesting, it is clear that AMD wants to get as much experience with multi-chippery on a single PCB as possible.

Two Radeon 3870 X2s working in pair. Note the longer Crossfire connector

As you can see in a picture above, the boards are connected via single bridge. The reason for first single-bridge appearance in ATI cards (HD2600 X2X has two bridges, just like regular parts) is the fact that one bridge is wired through the PCB and links the two GPUs locally, so "black magic" was not used in order to connect two the GPUs. Just logic and available resources.

This arrangement of four memory chips on back, four memory chips on top brings back memories of the Radeon 9700. Of course, the 9700 relied on old, DDR1 style memory working at 310MHz, while the 3870 X2 comes with memory almost three times as fast (GDDR3).

A look at cooler reveals that there are no visible heat-pipes

Beneath the cooler there are two chips. Each has its own 512MB of memory. But even with this board producing a decent amount of heat, this cooler does not use any visible heatpipes. It is just a longer version of the concept we saw with the 2900XT from the outside, but from the inside, there is nothing but copper fins.

This board will consume give or take equal power as a single 2900XT, and ATI opted to use one six-pin and one eight-pin PEG connector. With the 8-pin connector being specc'ed as a PCIe Gen2 requirement, it'so wonder that both AMD and Nvidia will use this connector in the future.

Catalyst 7.11 shows that Radeon HD 3870 X2 is already supported in the driver

Software support is already there. While drivers have to be significantly optimised for different applications, there are still around three Catalyst releases to go before the product is ready to hit the market.

Overclock two GPUs on a same PCB

ATI OverDrive is supported, and you can see that two GPUs work at 777MHz each, while 1GB of on-board memory is working at 901MHz, yielding a combined total of 115.32 GB/s.

The temperature tool will probably have to be tweaked to recognise the number of GPU cores on the board itself, but the interesting part will be just how much power savings RV670 can achieve.

It turns out that AMD is dead-serious about taking the RV670 to new heights. The firm is promising a whole lot, and seeing a system with two prototype boards running Call of Duty 4 with all bells'n'whistles in a Quadfire combination only leaves you thinking how great 2008 will be. It all started with three great products, Geforce 8800GT, Radeon HD 3850 and 3870, and as soon as Geforce 8850GX2 (or whatever Nvidia decides to call its dual-G92 series) and Radeon HD 3870 X2 make an appearance, we'll be ushered in a new era of affordable high-end computing.

According to AMD, the time of big and expensive high-end cards is over, everything is now about scalability. Nvidia is starting to sing the same tune.

It seems that both Nvidia and AMD finally learned that it is far better to create a monster of a mainstream chip that can be scaled with as many GPUs as you want. An eight to-16GPU setup is a possibility for both ATI and Nvidia, but don't think about games here. Think about medical imaging, videowalls and so on).

When the board debuts (current target is February) with higher clocked Phenoms (B3 rev), getting two of these cards will set you back anywhere between 800 and 1000 US Dollars or Euro, meaning buyers of four Radeon HD 3850s today will not lose their value when these two pop along. µ