Re:Intel x86 documentation has more pages than the 6502 has ...
by 0xcde4c3db on Thursday December 08, 2016 @10:10AM
(#13130723)
I think the backwards compatibility problem wasn't that it lacked backwards compatibility, but rather that the proposition was to pay more to run your existing binaries slower. I recall Pentium Pro having a similar problem with 16-bit code.
> When first released in 2001, Itanium's performance was disappointing compared to better-established RISC and CISC processors. - Wikipedia