This sale is for one rare 1991 MIPS R4000 CPU wafer manufactured by Performance Semiconductor. These 64 bit CPUs were used by SGI to build high performance workstation computers in the early 1990s.

The fully processed wafer has a mostly green tint depending on viewing angle and lighting spectrum. It is in excellent collectible condition.

Photos were taken under ordinary white florescent room lighting.

See many other tech collectibles in my ebay store.
 
Thanks for looking!