Bright Side of News claims the yields of NVIDIA's first batch of GT300 GPUs at TSMC are terrible, sources told the site that the chip is not yet ready for production as fewer than one out of three GPUs are working fine.
According to our sources close to the [silicon] heart of the matter, the problem that nVidia has are yields in the 20 percentage range. You've guessed, that is waaay [insert several "a"] too low for launching volume production and we probably will see a new revision of silicon until the yields get high enough to earn a little bit of money. Having three faulty chips on one working one is much too much, since those faulty chips aren't exactly "GTX 360" or "slower Quadro FX" grade material. Some faulty parts might work under forced cooling, but the high leakage is an issue with the current graphics card layout. We won't go into the whole instability, does not work etc situation.