PCB Design

Like any other RADEON X800 GT with 256MB of memory, the PowerColor X800 GT resembles the RADEON X800 XL because it uses a similar PCB. There are some points of difference but they are insignificant. The only really noticeable discrepancy is that the capacitors and coils in the GPU power circuit at the top left corner of the PCB are placed in a different manner. Of course, there is no additional power circuit with all its elements and power connector – the chip with only 8 enabled pixel pipelines consumes relatively little power in comparison with a full-fledged RADEON X850 XT GPU and the graphics card is quite satisfied with those 75 watts it can receive through the first section of the PCI Express x16 slot.

The reverse sides of the cards are also identical except that the PowerColor X800 GT lacks a few power elements in the GPU power circuit as well as a VIVO-supporting Rage Theater chip with its accompanying components. Since the card doesn’t support the video-in/out functionality, its PCB doesn’t have an additional 4-pin connector which is usually attached to a composite video output on the front panel of the system case.

Taking a closer look at the graphics processor you can see that it is an ordinary R480 chip manufactured on 0.13-micron tech process with low-k dielectrics. The chip on our sample of the card was dated the 49-th week of the last year, i.e. the beginning of December.

The R480 chip is losing its popularity, but it still makes sense to use this chip as well as the older R423 here because they are generally stable at frequencies about 475-500MHz while the 0.11-micron R430 is not (rare samples of that chip can work at least at 430MHz). The relatively high frequency ensures the RADEON X800 GT’s competitiveness against the GeForce 6600 GT and, perhaps, against the 12-pipelined GeForce 6600. By the way, the placement of the resistors on the die wafer is identical in both RADEONs. It means that the X800 GT had 8 of its pipelines disabled in the graphics card’s BIOS or in the chip registers.

It’s hard say anything new about the cooling system. PowerColor made use of an ordinary aluminum cooler with an axial fan which takes air from inside the system case and drives it through the ribbing section above the GPU die. This is enough to cool an R480 with only half the pipelines active and clocked at a reduced frequency. The blades of the fan are straight and narrow – not an ideal configuration as concerns noise (see the next section of the review). Dark-gray thermal paste, typical for ATI products, is employed as thermal interface between the graphics core and the cooler’s sole. Unfortunately, the memory chips on the face side of the PCB have no contact with the heat-spreader at all. The manufacturer must have decided to economize on elastic heat-conductive pads.

This device uses popular K4J55323QF-GC20 chips of GDDR3 memory from Samsung capable of working at 500 (1000) MHz frequency. The card clocks its memory at a lower frequency, 490 (980) MHz. The graphics processor works at 475MHz as we already mentioned above.