Early to mid 2000s, Athlon 64 and the Digital tech (as in DEC Alpha's EV6 bus) was where it was at, until Intel got back in front with Core 2. AMD got to define the 64-bit instruction set for x86 with Athlon 64. 2007 or so (13 years ago) was after the decisive swing back to Intel. I got a Q6600 in 2007 that I was using (in its final form in a NAS in the attic) until late last year.