A couple years ago I recall reading that back in the early 2000's there was enough gold in the central processing unit (CPU) and math-coprocessors to make it worth while to recover it computer recycling firms to smelt the chips to recover the gold from the prongs and heat transfer points.
As such, is there information in regards to the precise amount of gold actually used in the construction of both vintage processors (i.e. Intel 8080) and modern processors (i.e. AMD Phenom II)?
Here are some listings by processor for many CPU's, including sorting by yield:
Gold Content List in CPU Chips
Gold CPU Recycling Yields And Values
The second link covers some newer processors, like the core-duo, and lists it as "low yield".
Of note is this comment:
WARNING: Recycling can be very dangerous if you are not experienced. The chemicals used to extract the gold can be fatal if misused or inhaled.
It costs more in chemicals for someone on their own to do it.
It is only economical to do it on an industrial scale, e.g. thousands of processors, boards and more.
I believe the average processor is only electroplated and has between 3 pence and 10 pence of gold in it!
Quite frankly, you would probably get more for copper in a heatsink and scrap metal of the case than gold in a computer!
Of course 'CPU' means different things to different people. I think of it from a microelectronics point of view.
There won't be any gold to speak of in a silicon chip, but the packaging is a different story.
Gold plated contacts are used wherever good conductivity is required — and the high current consumption of modern cpu's makes them ubiquitous.
But the gold plating is very thin. As @William Hilsum said, it's only economical to reclaim the gold on an industrial scale.
