For well over a year Nvidia has remained at the top of the PC graphics market, holding the performance crown so comfortably they never looked as they might lose it.

Looking back in time we discover that the only threat from competition in recent times came from the Radeon HD 2900XT, which was never meant to defeat the GeForce 8800 GTX anyway. Then late last year we saw the arrival of the ATI Radeon HD 3870, though again this product was not in contention for the performance crown, although it served well its purpose of creating more value in the mainstream price points.

As we entered 2008, Nvidia remained and still is almost tight lipped about a true next-generation product that could push the performance envelope further. At the same time we were expecting AMD/ATI to hold its promise about a dual-GPU solution based on the Radeon HD 3800 that unlike conventional multi-GPU technology, would not require a Crossfire-compatible platform to work, and would become a real contender in the high-end graphics market.

We have to admit we were somewhat skeptical about the Radeon HD 3870 X2 when we were presented with the idea on paper. The single-card implementation of Crossfire could have easily transformed into big product delays and an overall less appealing product down the line. But AMD has proven itself this time, successfully launching the Radeon HD 3870 X2 on schedule, and perhaps even more important than that, having actual products on retail shelves immediately.

As you should know by now, the ATI Radeon HD 3870 X2 is essentially two Radeon HD 3870 GPUs stuck together on the same PCB. The GPUs use a PCI Express 1.1 bridge to communicate in much the same way Crossfire ATI cards would. However, because the X2 is meant to be a ‘transparent’ single card solution, it is still possible to use two of these graphics cards in Crossfire mode. Meaning that with the proper drivers, a quad-Crossfire system becomes a possibility.

Even before testing the X2, we could imagine the performance of two Radeon 3870 GPUs put together would be quite good, but as is the case with standard dual-card SLI or Crossfire, we also expected it to suffer from the same variance depending on the game run. And indeed, the performance of the Radeon HD 3870 X2 turned out to be quite close to that as you will see in our benchmarks.

But the brilliant part about the new Radeon design is that it doesn’t rely on drivers or a specific chipset to work (using the two GPUs in a single board). That said, we have still found the current crop of drivers (Catalyst 8.1 and 8.45) to be a little immature. While for the most part the system was stable during testing, every now and then we would encounter a random crash which did not appear to be specific to any game. Whether this is a problem related to drivers running on Windows Vista Ultimate 64-bit or not, we are unsure at this point.

The Card

Nowadays it’s more usual than ever to have graphics card vendors following ATI or Nvidia reference designs, and the Radeon HD 3870 X2 is no exception with most cards out there being identical to ATI’s reference design. However, in the short timespan that this product has been available, we were able to get a hold of another Radeon HD 3870 X2 card manufactured by ASUS. Improvements to this card include upgraded cooling, four DVI ports and a slightly overclocked core and memory frequencies. Other than that, the card’s PCB is essentially the same.

In terms of physical dimensions the ATI Radeon HD 3870 X2 is a beast, measuring 26.5cm long which is wider than a full ATX motherboard. The card dimensions are however very similar to that of a GeForce 8800 GTX/Ultra, so we are not entering unchartered territory. The appearance of this ASUS version is a bit different to the reference design and we rather like it.

Instead of using a plastic heat shroud, ASUS has gone with a brushed black aluminum housing that features two 65mm fan holes designed to cool both on-board GPUs. Removing the shroud will expose two small arrays of aluminum fins, the second of which has slightly more fins. These fins are each connected to a copper base plate via two sets of heat pipes. Realistically this cooling setup is no more extreme than the reference design and we found it to be a little underpowered at times.

Separate from the new cooling design you will notice a large steel plate at the front of the graphics card labeled ‘DUAL’. When moving around to the back plate you will discover that there are not two, but four DVI ports just as there would be with a Crossfire setup. Those seeking serious connectivity for LCD monitors will no doubt be every interested on this feature, as two cards will support eight DVI ports!

The ATI Radeon HD 3870 X2 comes with 1GB of memory (512MB assigned to each GPU). The default operating specification for this memory is 1800MHz, though ASUS has increased the frequency to 1910MHz on their TOP edition of the card. Furthermore each GPU has been designed to work at 825MHz, while ASUS has overclocked the TOP edition to 850MHz. This is only a 3% overclock per GPU, so we can only imagine they were hitting limitations inherent to the complexity of the board design.

On the upside, ASUS is using 1GB GDDR3 .8ns memory from Hynix “HY5RS123235B FP-08” memory which overclock rather well. We were able to reach 2122MHz with these moduals before stability became a problem. The cores on the other hand were limited to 861MHz, which is only 11MHz higher than the already slightly overclocked speeds.

Benchmarks: System

As a single card solution, the Radeon HD 3870 X2 used slightly less power than the GeForce 8800 GTX at idle, while requiring considerably more power when under load. In fact when stressed in Crysis the 3870 X2 used 23% more power than a GeForce 8800 GTX.

When compared to the Crossfire Radeon HD 3870 setup however, we found the 3870 X2 to use 9% less power. This is unlike other results we have seen online, but we can assure you we triple checked our measurements.

We were delighted to see the upgraded ASUS cooling solution to work this well, as the Extreme AH3870X2 managed to run slightly cooler than a single Radeon HD 3870 graphics card. Nevertheless a stress temperature result of 80 degrees is still far too high for our taste, when all that hot air is being circulated through the case. I guess we will have to wait for Arctic-Cooling to make an Accelero Xtreme for the Radeon HD 3870 X2 before we see better stress temps.

Final Thoughts

Better late than never, AMD/ATI has done it. There is no question that the Radeon HD 3870 X2 is the fastest single card solution on the market today.

We were impressed with the capabilities of the new Radeon, particularly because once installed it was easy to forget we were working with two GPUs on-board. The 3870 X2 worked seamlessly with every game we threw at it, there were no Crossfire settings to mess with, and we could simply sit back and relax as we played.

The performance of the Radeon HD 3870 X2 is more solid than we initially expected, as it delivered very similar performance to a Crossfire Radeon HD 3870 setup. The advantage being that the Radeon HD 3870 X2 costs slightly less than a pair of Radeon HD 3870 graphics cards at £225, and it will work on virtually any motherboard boasting a PCI Express x16 slot.

Besides the odd crash here and there that we believe is strictly driver related, the ATI Radeon HD 3870 X2 worked well. Of course, we are hoping that all these minor stability issues are ironed out on the next Catalyst driver release. Then the only other concern we could have is that the card runs a bit hotter than we would like, dumping a lot of hot air in the case, though this is not unique to the X2 and many of today’s high-end cards generate more or less the same amount of heat.

We are pleased with ATI’s achievement although ironically they got here using an existing product which makes this victory a little less impressive. The way things are right now, Nvidia will probably find a way to turn things around and create a dual G92-based graphics card, which could put Nvidia out in front again.

But talking strictly about the present, in terms of value, just recently we bought two GeForce 8800 GT 512MB cards for about £230. Given the performance advantage this SLI setup had over the Radeon HD 3870 X2 in a number of tests, we must ask ourselves which setup is the better buy. Furthermore, two GeForce 8800 GT 256MB cards cost just over £200, which could make the choice even harder.

For now the Radeon HD 3870 X2 stands as the fastest single card solution out there and as a convenient alternative to both Crossfire and SLI that require two matched cards and a supporting motherboard. Let’s see what Nvidia comes up with in the months ahead…