NVIDIA GeForce FX 5900 XT
“XT” suffix by the graphics cards based on NVIDIA processors means just he opposite thing compared to what the same “XT” by ATI stands for. It is probably in order to “please” ATI that NVIDIA marked its slower GPU modifications with the “XT” suffix, while ATI uses it to mark the faster VPU modifications, as we all know.
GeForce FX 5900 XT is a lower-cost modification of GeForce FX 5900.
Unfortunately, we failed to find out what company produced this graphics card, however, we suspect that it was the Chinese Colorful Company. The PCB layout of this graphics solution looks very similar to that of other GeForce FX 5900 XT based products.
In fact, the components layout is very much different from what NVIDIA suggests with its GeForce FX 5900/5900 Ultra, as our hero is a low-cost modification. For instance, all memory chips are placed on one end of the PCB, which made the wiring much simpler. The chips are slower and hence cost less than those memory chips they use for GeForce FX 5900/5900 Ultra. The memory chips are located not in a half-circle, but in two rows, which allows using simple square heatsinks for their cooling. Finally, the voltage regulators for the GPU and graphics memory do not look that monstrous any more as those we saw on NVIDIA GeForce FX 5950 Ultra or GeForce FX 5900/5900 Ultra. Probably lower working frequencies of the GPU and graphics memory allow reducing the requirements to their voltage regulators.
As a result, we get a very nice product. Firstly, this card is pretty quiet and its cooling system doesn’t occupy the space around the next PCI slot. And secondly, the card is equipped with a fully-fledged NV35 graphics processor and 256bit memory bus, and its working frequencies are not that much lower than those of the top-end products.
The GPU and the graphics memory of our graphics card work at 400MHz and 700MHz respectively. The card is equipped with 128MB of DDR SDRAM graphics memory in8 BGA chips from Hynix with 2.8ns cycle time (Hynix HY5DU283222 AF-28).
After overclocking the GPU and the memory of our graphics card worked at 440MHz and 860MHz respectively.
GPU appeared very poorly overclockable, which was quite a surprise, as I expected it to reach at least 450MHz, as GeForce FX 5900 XT, 5900 and 5900 Ultra are physically the same. GeForce FX 5900 XT is very unlikely to be a defective GeForce FX 5900, i.e. NV35 chip, which is not capable of working at a certain frequency, because the nominal working frequency of the XT solution is the same as that of the GeForce FX 5900. However, when we overclocked the card to 440MHz it refused to work stably. Maybe I just was unlucky and got not the best overclockable piece, or maybe I had to use a better cooling system to achieve higher results.
The graphics memory, on the contrary, appeared highly overclockable: the maximum working frequency of these memory chips is 714MHz, as the marking suggests, so the 860MHz we managed to squeeze out of this memory is an excellent result, I should say.