The Radeon X1900 XTX Reference Board from ATI

We disassembled the video card heatsink to take a look, see Figure 4. If you pay close attention you will see that the base of the heatsink – the part that touches the graphics chip – is made of copper. The heatsink fins are also made of copper. The fan blows the hot air to outside the computer case, helping a lot to decrease the PC internal temperature. But, because of this blower, besides the x16 PCI Express slot this video card uses the slot right next to it (usually a x1 PCI Express slot).

Radeon X1900 XTXFigure 4: Heatsink from the Radeon X1900 XTX reference board.

Radeon X1900 XTXFigure 5: Video card with its heatsink detached.

This video card uses eight GDDR3 512-Mbit 1.1 ns chips from Samsung (K4J52324QC-BJ11)to give it 512 MB of video memory (512 Mbits x 8 = 512 MB). These chips can run up to 1.8 GHz. Since this video card accesses the memory at 1.55 GHz, there is 16% headroom for overclocking the memory keeping it inside its specs. Of course you can try overclock it over its specs.

Radeon X1900 XTXFigure 6: 1.1 ns GDDR3 memory chip used by ATI Radeon X1900 XTX reference board.

The reference board has video capture function (VIVO), using ATI Rage Theater chip.

Radeon X1900 XTXFigure 7: ATI Rage Theater chip for video capture.


Gabriel Torres is a Brazilian best-selling ICT expert, with 24 books published. He started his online career in 1996, when he launched Clube do Hardware, which is one of the oldest and largest websites about technology in Brazil. He created Hardware Secrets in 1999 to expand his knowledge outside his home country.