ATI's Midrange Rebuttal: Radeon X1800GTO, Continued

The main difference is that the X1800GTO core has one of its pixel shader quads disabled. Each quad is able to process up to 128 threads from the dispatch processor. This means that the X1800GTO can handle up to 384 threads at a time. Other than this one main core difference, the X1800GTO is identical to its sister chip.

The core and memory frequencies are also slower than the X1800XT as well. The vertex and pixel shaders operate at a frequency of 470 MHz. The GDDR3 memory still operates on a 256-bit wide bus and at a 500 MHz base frequency.

The card will not be officially produced as an ATI retail packaged card. ATI cannot guarantee the exact date when their partners will have boards on store shelves but emphatically stated Radeon X1800GTO cards would be available by the end of the month. ATI hinted that it would probably be much sooner but they could not disclose the release dates for these other companies.

This Radeon X1800GTO is capable of running in CrossFire mode if it is coupled with a Radeon X1800 CrossFire Edition master card. The X1800GTO will run slower than the master card, which will be more expensive than the X1800GTO. However, ATI plans on launching a Catalyst version later this year to address this. The driver will allow two X1800GTO cards to run in Crossfire mode without the need for the external cable or a Crossfire edition master card. This would make the X1800GTO the third card that is capable of achieving multi-GPU functionality across PCI Express, the others being the X1300 and X1600 series cards.