As with the worst kind of tequila, we usually take these kinds of rumours with a tight pinch of salt. However, a GPU-Z screenshot and a 3DMark06 score, all of which look pretty legitimate, back up the latest leaks concerning Nvidia's forthcoming GeForce 9800 GTX.
Expreview and VR-Zone have spilled the beans, revealing that the GeForce 9800 GTX is a very similar beast to the 512MB GeForce 8800 GTS. If the screenshots are to be believed, then the 9800 GTX has 128 stream processors, 512MB of GDDR3 memory and 16 ROPs, although it has slightly different clock speeds from the 512MB GeForce 8800 GTS.
According to the GPU-Z screenshot, the 9800 GTX has a very high shader clock of 1.69GHz, a core clock of 675MHz and a memory clock of 1.1GHz (2.2GHz effective). This isn't wildly different from the 8800 GTS in terms of clock speeds, but it may well be much quicker if the results from the GeForce 9600 GT are any indication.
The 9600 GT might have been overpriced in terms of performance, but it had an impressive amount of power for a GPU with just 64 stream processors. If the 9800 GTX uses the same streamlined architecture, then it may well prove to be much quicker than the 8800 GTS, despite having very similar specs on paper.
Expreview has demonstrated the potential speed of the card with a 3DMark06 score of 14,014 at 1,280 x 1,024 using a Core 2 QX9650, but this is the only benchmark we've seen so far. It's also worth noting that 3DMark06 only tests DirectX 9c features, and won't really challenge the DirectX 10 hardware.
As with the 9600 GT, it looks as though the 9800 GTX still doesn't support DirectX 10.1 either, although this is more of a marketing checkbox at the moment as DirectX 10.1 hasn't even been officially released yet.