It seems like only yesterday we were looking at ATI's Radeon X1800XT for the first time. Actually though it was three and a half months ago that the X1k series launched. Since then there was a small refresh of ATI's high end part with the introduction of the X1800XTPE (a higher clocked version of the standard XT) and more recently the launch of the X1800 master cards. When you add into this the fact that ATI also launched the AIW X1800 and AIW 2006 PCIe Edition after the X1k launch it's certainly not been a quiet time for ATI.

Today's launch is one which may come as a bit of a surprise to many people. It's not uncommon for manufacturers to refresh their product lines regularly however what doesn't usually happen is the introduction of a much faster part only 3 months later than the part its replacing. ATI have decided to do that so let's see what the new X1900XTX and X1900 Crossfire are all about.

X1900 Hardware

X1900 Crossfire Edition

As with previous generations of Crossfire the X1900 series uses a master and slave configuration, let's look at the master card to begin with.

The front of the card is very similar to the X1800XT, you have ATI's now standard Dual Slot cooler is used featuring a Ruby graphic. The PCIe power connector is also featured as normal and the passive heatsink running down the right side of the card remains. Specification wise the X1900 Crossfire Edition uses a R580 core (featuring 48 pixel shader units) clocked at 621mhz Core and 720mhz Memory ( 512mb GDDR3).  To allow you to compare the X1800's Crossfire Master used a R520 core clocked at 625mhz coupled with 512mb of GDDR3 running at 720mhz (16 pixel shader units).

Many of the initial X1800 cards released feature a 5 power coil design, this was changed on the XTPE and Crossfire cards more recently by a 6 coil design. With the X1900 we see a further increase and as the picture below shows the X1900 features 7 power coils and associated circuitry.

The rear of the card is a pretty standard affair as you can see from the picture below.

Turning the card back over and removing the cooling we can see the Crossfire components more clearly. The X1900 crossfire master card uses the same design as the X1800 CF card. This includes Silicon Image 163B dual-link TMDS receiver chips which are partly responsible for allowing the X1900 Crossfire to process resolutions above 1600x1200. The maximum resolution available by combining the 2 SI receivers (running at 165mhz and capable of receiving 2x1600x1200 @ 60hz) with the new more powerful composing engine is 2560x1600. The second type of SI Chip which you can see (right hand side) are TDMS transmitters which is used to output the signal to any displays connected to the master card, again there are two such chips on the master.

The next major part of the Crossfire hardware sits directly beside the SI chips and is the Xilinx Spartan XC3S400 FPGA, a programmable logic chip which handles the image composing (including blending for Super AA mode). Interestingly this chip is programmable and can be flashed should ATI decide to add features to the design in the future.

Finally, turning to the side of the card we can see the cards bracket allows you to identify it as a master card immediately, whilst you have a DVI port as normal you also have the new style crossfire connector for the higher spec Crossfire cable. No additional video out though on the master card.

Also included in the pack with your master card will be the Crossfire connection cable, ATI use the same model with the X1900 series that was used with the X1800 series.

Currently ATI are using the existing crossfire chipset for their full range of products. The chipset codenamed RD480 is the basis for many retail motherboards such as the DFI LANParty UT RDX200 CF-DR, Asus A8R-MVP and Sapphire PURE Crossfire and all work in the same way. Just plug in your master to the lowest numbered slot and your slave to the 2nd slot and your good to go as far as your systems internal workings are concerned (This results in you using two 8x pcie slot mode rather than two 16x slots as with some SLI systems).