While the X800GT was supposed to compete against the GeForce 6600GT from nVidia, the X800GTO is up against the non-existent GeForce 6800XT from nVidia. Since we don't have the 6800XT and information that can be trusted, we are looking at the X800GTO as more of a beefed up version of the X800GT.
With a core clock of 475MHz and a memory speed of 500MHz we find that the core is actually slower then the X800GT which comes clocked at 500MHz and the memory speed is running at the same speed.
Like the X800GT, the X800GTO comes with Samsung 2NS DDR3 modules. While clock for clock the X800GTO does look like the slower card, it does utilize a 12 pixel pipeline architecture as opposed to the 8 pixel pipeline on the GT version.
There are two key factors when it comes to speed - raw MHz being the core and memory speed along with the amount of pipelines. While normally we find that cards with more pipelines are usually faster, if the core and memory speed is extreme enough a card with less pipelines can perform just as well as another with more pipelines.
For example, with the X1800 due out soon with a 16 pixel pipeline architecture there is no doubt that a much higher core and memory speed will be used for it to compete against the 24 pixel pipeline nVidia offering we call the 7800GTX.
Now we know more about what powers the X800GTO, let's take a look at the sample card from GeCube.