A closer look at the Radeon X1900XTX
Visually, in many ways the X1900XTX is quite similar to the X1800XT. Both are the same size, weigh the same, both use the same reference cooler and the PCB layout is pretty much identical. Again, a very heavy duty dual slot cooling solution is used like the X1800XT which is used to exhaust hot air out the back of your case. You also will still find the 6-pin power connector as the PCI Express connector is not able to provide enough power for the X1900XTX.
The X1900XTX we tested at the Gigabyte offices is actually a reference sample with a Gigabyte sticker on it. Don't be alarmed though; initially ATI make all the graphics cards for their customers and later on companies such as Gigabyte may choose to make the card themselves and push for higher clock speeds and maybe attach some fancy cooler which is quieter or has some type of special features.
The X1900XTX comes with default clock speeds of 650MHz on the core and 775MHz (1550MHz DDR) on the memory which seems to be yielding well for ATI and comes with a total of 512MB of memory. The memory used (K4J52324QC-BJ11) on the XTX version of the X1900 series is very fast (and expensive) GDDR-3 memory from Samsung at 1.1ns which operates at 2.0 volts. That means it is capable of running at 900MHz or 1800MHz DDR - which is of course, extremely fast. This could be an indicator that the XTX will be a good overclocker in the memory department and later on companies might bring out X1900XTX OC version with some insane memory clock speeds to help keep nVidia on their toes.
Compared to the previous generation X1800XT, the X1900XTX is only a little quicker in terms of the pure clock speed numbers. The X1800XT has a core clock speed of 625MHz and memory clock speed of 750MHz (or 1500MHz DDR) using 1.2ns memory. Don't let the pure clock speeds numbers fool you though as the X1900XTX is able to process a lot more per clock in terms of shader performance. The X1900XTX has 16 pixel pipelines each with three pixels shaders for a total of 48 shaders compared to a maximum of 24 pixel pipelines on the GeForce 7800GTX 512. The X1800XT only has 16 pixel pipelines, so the increase in processing power is huge.