CPU-Collection.de
A German website featuring a collection of obsolete CPUs. Information about package and socket types. The collection can be viewed by manufacturer or family. It also features a shared forum with cpu-museum.de.
CPU-Collector.com
Large CPU collector web site that features a searchable collection, from early vintage to more modern models, with photos, information, specs, and forum. Includes many non Intel CPUs (ex Motorola and Cyrix).
CPU-Museum.de
German collection of early to late model cpus with photos and specs. It also features an interactive forum.
CPU-World.com
Large CPU collection organized by manufacturer and class. This site features a variety of identification tools and forum.
CPUShack.net
A rather large collection of CPUs and other support chips. The site features a photo directory organized by manufacturer.
X86-Secret : ES Zone
An Engineering Sample (ES) only CPU collector web site. This site features an extensive collection of engineering samples and prototypes (mainly x86 architecture).