Who released the first multi-core processor?

[Prosthetic_mind]

I'm doing a paper on the history of multi-core processing, and I'm having a hard time getting good results. When I search for the first dual-core processor, I ultimately get pages that fall into 3 consensuses, either AMD released the first dual core processor, Intel did, or IBM did, with the Power 4 chip. Which of these is right? And if anyone has some good potential sources I would greatly appreciate it.

Edit: shoot, I guess this should have gone in core hardware, my bad.

[PrntRhd]

A search shows IBM had a dual core processor released in 2001:
http://en.wikipedia.org/wiki/POWER4

Not only did the POWER4 become the first microprocessor to incorporate dual-cores in a single die, it also was the first to implement a Multi-Chip Module (MCM) containing four POWER4 Microprocessors in a single package.

AMD's Opteron was released in April 2005.

[saphalline]

Define "microprocessor" and "multi-core" as it relates to your question.

[Prosthetic_mind]

ultimately I'm looking at the consumer market CPUs, and by multi-core, I mean having more than one "execution core"(wikipedia's terminology) in the aforementioned CPU.

Edit: Basically I'm looking at stuff in the consumer market, like the Opteron and the Athlon 64 x2. I'm not completely sure what you're getting at

[saphalline]

Ok, so are you also considering RISC-based VLIW microarchitectures? And are you using the definition of a multi-core CPU as being limited to single-die? How does SMP play a role here? By execution port number or instruction type or processing ideology?

[Prosthetic_mind]

how about we start with the first microprocessor that could technically be considered a multiple core processor, and then move to the first one that came to be used prominently in the open market for PCs.

Edit: also, if it makes it any easier for you, I'm in the chat room right now, and will be for quite some time.