I don't know for sure, but I think it'd be the 8088.
The Intel 4004 introduced in 1970 and was the first processor introduced by Intel.
As its a 4XX model, it is a first generation Intel Core i5 processor.
Intel's first 64 bit processor
The first intel processor introduced in 1973 called is Intel 8008
The Intel Pentium Pro was the first Intel processor to contain level 2 cache.
Intel 386 processor, released in October 1985
It is not possible for a person to upgrade their PowerPc G4 eMac to an Intel processor. This is because the computer model is severely outdated and isn't compatible with the Intel processor.
The first processor to contain L2 (external) cache was the Intel Pentium Pro.
In 1974, the Intel 8080 was introduced.
The Intel 8088.
All microprocessors, from Intel and others, have had known errata. Without knowing the model of the processor in question, I can't be specific in listing the errata.
The first CPU chip was released on November 15, 1971 by Intel. The processor was called the Intel 4004 and was a 4-bit CPU.