Closer Look

The ASUS AX800 XT/TVD differs but slightly from the junior model and that’s normal as all X800 family cards use the same reference PCB design.

In this particular case, all outward difference from the AX800 PRO boils down to the AX800 XT’s having a yellow connector near the additional power plug and a Rage Theater chip with its smaller companion logics. The yellow connector looks like an audio input but is actually intended for attaching an additional video input which can be placed, for example, on the front panel of the system case.

Besides these external differences, there are internal ones, which are even more important. Particularly, the ASUS AX800 is equipped with faster GDDR3 memory from Samsung with an access time of 1.6 nanoseconds (against 2ns memory of the AX800 PRO). Like becomes a decent RADEON X800 XT, this one clocks its memory at 560 (1120DDR) MHz and its GPU at 520MHz. All the 16 pixel pipelines are in operation now, too, while the AX800 PRO (and any other RADEON X800 PRO for that matter) has only 12 operational pipelines.

The cooling system has been inherited from the AX800 PRO, with the same disadvantage – the memory chips are not cooled down at all, although ASUS could have easily realized that. The memory on the AX800 XT is clocked at a higher frequency than on the AX800 PRO, so it just demands cooling but never receives it. Running a little ahead, we should confess that the graphics card we tested would overheat often during our tests as the weather was rather hot these days here. Overheat led to frequent hang-ups which we only managed to prevent by installing an additional 120mm fan to blow at the card from its butt end. The air stream was being cut in two by the card’s PCB and was reaching to both front and back sides of the PCB, cooling the memory chips. We would have been spared the trouble if ASUS had put thermal pads on the memory chips under the cooler’s sole and passive heatsinks on the backside memory chips. Considering the more intensive heat dissipation compared to the AX800 PRO, we think the AX800 XT needs to be installed into a system case with additional air cooling and a well-thought configuration of airflows; otherwise you may find your card overheating too often, especially in summer.

Overclocking, Noise, and 2D Quality

All the praises we showered on the ASUS AX800 PRO for its noiselessness and excellent 2D quality can be applied to the AX800 XT, too. The cooler is only heard for a couple of seconds after you’ve powered the computer up, but then it slows down to become almost completely silent. On the GPU hitting a certain threshold temperature, the cooler increases its rotational speed, but this hardly ever happens.

2D quality was no worse than with the junior model: the AX800 XT was outputting a crisp image in all resolutions supported by our monitor, up to 1800x1400x@75Hz inclusive.

Overclocking, on the contrary, was rather average. With additional cooling, we managed to overclock the core to 555MHz as the card was unstable at higher core frequencies. The memory pleased us even less, only speeding up to 570 (1140DDR) MHz. Again, at higher memory frequencies, we had all manner of artifacts onscreen and frequent hang-ups. Water or cryogen cooling might have helped us more, but these are not really inexpensive and simple ways to improve the performance.