When this news broke many were curious -- which GPUs were affected and what exactly is the problem?  Well the answer to the latter is relatively simple -- a number of NVIDIA mobile GPUs had extremely poor thermal tolerances thanks to defects.  This leads to early chip death and faulty behaviors, such as artifacting, as chips start to fail.

The answer to the first question -- how many -- is just now becoming clear.  It appears appears that NVIDIA's mobile offerings are much harder hit than initial conservative estimates.  Dell and HP, the two largest computer manufacturers have just released lists of what computers have defective chips.

It turns out virtually all the NVIDIA mobile chips are defective.  NVIDIA tried to brush off the issue stating that the issue was a "previous-generation" problem.  However, it turns out that virtually all 8400M and 8600M chips are defective.  These chips make up the bulk of NVIDIA's higher end graphics offerings.  While NVIDIA started to roll out the first of its 9 series mobile chips, the 8 series represents the flagship line of its mobile offerings.

The low to middle end chips are also virtually all defective.  Among the defective lines are the GeForce Go 7000 and 6000 lines, as well as the Quadro NVS 135M and the Quadro FX 360M.

In order to respond to the problems HP is offering extended warranty support.  Information is available here.  Dell offers a driver fix which attempts to deal with the heat issues by pumping up fan speed, on top of its standard warranty support. 

According to Dell, signs of GPU failure include multiple images, random characters appearing onscreen, lines on the screen, or no video at all.  Dell claims the updates will not affect battery life.  Its new Vostro line of notebooks is shipping with the fix preinstalled.

While Dell's solution may provide a decent stopgap to carry chips outside the warranty, it seems unlikely to be able save the chips from a shorter than average lifetime.  In the end both with Dell and HP the warranty charges will eventually be passed on to NVIDIA.

Also, the fact that the bulk of its mobile GPUs, a major source of business, are defective is also extremely troublesome for the giant.  However, as ATI/AMD showed with its latest series of GPUs, in the graphics industry you can never rule out a comeback.

For those with mobile GPUs from other manufacturers, please refer to their respective pages as many of them have posted or will be posting information on the problems.