PCB Design and Cooling System
The Gigabyte Radeon X1900 XTX is an ordinary Radeon X1900 XTX manufactured for ATI and doesn’t differ at all from the reference card:
Only three things indicate that it is a Gigabyte version of Radeon X1900 XTX: the sticker with the model name near the PCI Express x16 slot, the picture on the cooler’s casing, and the Gigabyte logo at the bottom of the blower. The reference cooler is quite efficient, so Gigabyte didn’t try to experiment with it. There’s nothing particularly interesting on the reverse side of the PCB, just various stickers with serial numbers. The cooler is fastened reliably and safely for the PCB with 8 screws. There’s a metal back-plate with dielectric pads to ensure that the heatsink’s sole is uniformly pressed down to the GPU die.
The Gigabyte Radeon X1900 XTX has eight chips of GDDR3 SDRAM on board (Samsung’s K4J52324QC-BJ11 chips in 136-pin packaging). The total amount of memory is 512MB and it is clocked at 775 (1550) MHz, exactly as described in the Radeon X1900 XTX specification. This memory, however, is rated for work at 900 (1800) MHz and we are going to try to overclock it to this frequency.
The graphics processor is clocked at 650MHz, as described by the Radeon X1900 XTX specification, too. Thick dark-gray thermal paste with low thermal resistance is used as a thermal interface between the GPU die and the heatsink’s base; the memory chips contact the heatsink via elastic thermal pads. This should be enough considering that the power consumption (and, accordingly, heat dissipation) of K4J52324QC-BJ11 chips is very low – 2.6W per chip at maximum when clocked at the nominal frequency.
There’s no sense in describing the cooler installed on the Gigabyte Radeon X1900 XTX in details as we did it a number of times in our earlier reviews. In brief, the cooler consists of a massive copper well-ribbed heatsink equipped with heat pipes and covered with a plastic casing. The blower set up behind the heatsink drives air from within the system case through to heatsink and then exhausts it to the outside. So, this cooler help keep the system case temperature low, but there are some imperfections in ATI Technologies’ implementation. Particularly, the plastic casing acts as a resonator, adding an irritating plastic note to the sound of the blower when the latter works at an increased speed. Besides that, the reference cooler from ATI is very heavy due to the copper heatsink with a thick sole.
Like every other Radeon X1800/X1900 card, the Gigabyte Radeon X1900 XTX supports VIVO through a Rage Theater chip. This functionality isn’t in great demand in our era of digital video, but sometimes you may need to connect an analog video source to your PC.
Since two graphics cards from Gigabyte are covered in this review, we are going to show you the next one, Gigabyte GV-NX79X512DB, before proceeding to overclocking and gaming tests. Gigabyte’s products having not very clear model names, we will refer to the next card as to Gigabyte GeForce 7900 GTX.