Everybody has had at least once the curiosity of considering multiple video cards on a single computer. But not just for the fun of having them there. We always want better performance. And what’s better than one GPU?

Two GPUs. Why not even three of four.

The ATi CrossFire (or AMD CrossFire, however you want to name it) technology provides you just that option. To combine up to four discrete graphics processor units (ATi Radeon HD, of course) so you can make your system’s video power good enough for more demanding games.



The first public mention of CrossFire was even before AMD purchased ATi, somewhere in late 2005. A condition of using this technology is using a compliant motherboard. The first version of CrossFire connected only two PCI Express graphics cards. In this first generation of Crossfire technology, one video card had to have a master capability, which had extra chips that combined the data from the two cards.

There were some limitations to this technology though. Take, for example, the Radeon X850 (which had the master capability): due to hardware limitations, the maximum display resolution was 1600 by 1200 pixels with a refresh rate of 60 Hz, or a higher one, of 1920x1440, but with an even lower refresh rate of 52 Hz. The first one doesn’t seem like a problem nowadays, when the majority of users use LCD monitors on which a 60 Hz refresh rate is not a problem. But back then, there were CRT users that were annoyed by these features, because such a small refresh rate on that kind of monitor is really awkward for the eyes.

The second generation of CrossFire came with an improvement. When a special chipset is used on the motherboard, namely the CrossFire Xpress 3200, there is no need for a master card for every video card that implements this technology. On this kind of chipset, the two video cards can communicate using the PCI-E bus.



Nowadays we are witnesses to the latest generation of CrossFire, also known as CrossFireX. With this technology, the master card is no longer needed. Video cards that implement this technology are connected through ribbon connectors and you can combine up to four GPUs. The funny thing is that this technology doesn’t benefit only high-end video cards. You can combine two entry-level video cards to really boost your performance in games. The CrossFireX is similar to Nvidia’s SLI in some aspects. But the SLI only works between cards with the same GPU. The CrossFireX can combine different GPUS, but from the same generation.

There is one more CrossFireX mode, known as Hybrid CrossFireX, which can combine on-board GPUs with different graphics cards. If you’ll have the curiosity to check out more about CrossFire on their website, there is also a comparison chart that shows all the possible combinations using this technology.