2021-03-14 7:19 GMT-04:00, The Wanderer <wande...@fastmail.fm>: > On 2021-03-14 at 06:49, Susmita/Rajib wrote: > >> While Intel PCs are also 64bit processors? > > Because of the history of the processor microarchitectures involved. > > The x86 processor line (32-bit and older) was, to the best of my > knowledge, originally an Intel thing. Before i386 (where the 'i' may > stand for Intel, I'm not sure), there was 286, and other things earlier > than that; if my memory just offhand is accurate, the oldest one was > probably called 8086. After i386, you have 486, 586, and 686; current > Debian 32-bit packages are actually compiled against the 686 baseline, > not 386 as such. > > Intel owns the patents for the 32-bit x86 CPU architecture, and licenses > them to other companies for a price. AMD is one of those other > companies; that's how AMD is allowed to create 32-bit x86 CPUs. > > When 64-bit came along, rather than extending the x86 line, Intel > started from scratch and designed an entire new CPU architecture. That > got called ia64, and it never caught on; it eventually failed in the > marketplace, except possibly in very limited market segments. > when Intel created a 64-bit architecture (called ia64), it turned out to > be a developmental dead end and failed in the marketplace. > > At around the same time, AMD created a 64-bit CPU architecture which > extended the x86 line, and was backwards compatible with existing > software. That got called amd64, and is also sometimes called x86_64, or > other names in addition. It caught on, and became so successful that > Intel abandoned its ia64 approach and started making amd64 CPUs itself. > > AMD owns the patents for the 64-bit amd64 CPU architecture, and licenses > them to other companies for a price. Intel is one of those other > companies; that's how Intel is allowed to create 64-bit amd64 CPUs. > > > Or, put briefly: because AMD created the underlying design for how that > type of CPU works, even if Intel is the one making the specific CPU > model in question. > > Does that make sense?
Perfect explanation. Also very good all those additional contributions from the others.
