Board analysis

Like the Radeon X800 GT/X800 GTO, ATI’s Radeon X1800 GTO starts life out as a high-end GPU that’s been adapted for use in the mainstream market. In the case of the X1800 GTO, ATI relies on the exact same R520 GPU that was used previously in Radeon X1800 XT/X1800 XL graphics cards, only they’ve disabled a few of the GPU’s features in order to serve the mainstream market.

The most critical change comes to the X1800 GTO’s pixel shading units. Whereas the R520 GPU housed inside Radeon X1800 XT and X1800 XL cards ships with 16 pixel shaders, for the X1800 GTO four of the pixel shader units are disabled for a total of 12. In addition to disabling these pixel shaders, ATI also deactivates four texture units as well as four ROPs (down from 16 in the X1800 XT/XL) for the Radeon X1800 GTO. Fortunately, the vertex shaders carry over unchanged from the X1800 XT/XL at eight.

In terms of clock frequencies, the graphics core and memory on the X1800 GTO are both clocked at 500MHz, this is the same clock speed as the graphics core and memory on the X1800 XL.

Because of these changes, fill-rate of the X1800 GTO drops from 8,000 Mtexels/second on the X1800 XL to 6,000 Mtexels/second on the X1800 GTO. Since the X1800 GTO shares the same 256-bit external memory interface as the X1800 XL, memory bandwidth peaks at 32GB/sec. These figures compare pretty favorably in comparison to NVIDIA’s GeForce 7600 GT, which boasts a texel fill-rate of 6,720 Mtexels/sec and memory bandwidth of up to 22.4GB/sec.

Top of the PowerColor X1800 GTO

Bottom of the card

Dual DVIs

PowerColor’s X1800 GTO

PowerColor’s Radeon X1800 GTO card is one of the first GTO boards to hit the market. It supports all the key features of the X1800 GTO we just mentioned, namely its clocked at 500/500 and sports the same 12 pixel shader architecture as ATI’s Radeon X1800 GTO, as well as being outfitted with 8 vertex shaders. PowerColor even equips their X1800 GTO board with ATI’s Rage Theater chip, providing video-in/video-out (VIVO) capability as well as dual DVI connectors.

Another comparison of the X1800 XT 512MB and X1800 GTO

ATI X1800 GTO reference design compared to the final X1800 GTO from PowerColor

Note the different fans used for cooling

Looking at the board itself, we see that ATI and their board partners have made a few changes to the final X1800 GTO board design since we first took a look at a pre-release reference GTO board from ATI last month. Whereas the original GTO reference card was based entirely on the X1800 XL board design, the PowerColor Radeon X1800 GTO board we’re taking a look at today has incorporated one key change: a slightly redesigned cooling unit.

The heatsink cooling the GPU itself is still copper-based and basically unchanged from the X1800 XL heatsink used previously, only now the duct sitting atop the copper heatsink has been redesigned to accommodate the new fan used to the cool the X1800 GTO’s GPU: whereas the original fan used on the X1800 XL and early X1800 GTO boards was small, it has now been swapped out with a much larger cooler.

Copper heatsink

Another shot of the cooler

With the larger fan in place on the PowerColor X1800 GTO, the fan no longer has to spin at the high RPMs that the previous fan required in order to cool the GPU. As a result, the PowerColor X1800 GTO board doesn’t generate as much noise as ATI’s X1800 XL cards did. This should make PowerColor’s Radeon X1800 GTO card more ideal for use in home theater PCs, or any application where noise is a concern for that matter.

Software and accessories

Rather than rely on a game bundle with their Radeon X1800 GTO card, PowerColor instead provides a DVD-ROM containing several CyberLink programs: PowerDirector (for video editing), MediaShow (photo slideshow), MusicMatch (MP3 ripping and playback), PowerBackup (Data backup), PowerDVD (DVD Movie Playback), PowerProducer (DVD authoring and burning), Power2Go (Data/music burning), and PowerDVD copy (one-step DVD copy). Also included with the card are two DVI adapters, a 6-pin PCI-E power adapter, S-Video and composite video cables, a component video cable, and VIVO cable. We should also note that PowerColor’s Radeon X1800 GTO doesn’t come with a lifetime warranty at this time. Earlier this year PowerColor announced their lifetime warranty program, but this only applies to their X1900 cards.