The Barcelona chips initially had a pretty nasty bug in the TLB. AMD stopped shipments for about 5 months so they could put out a new stepping with the bug fixed. The Istanbul chips arrived a few months after Intel's Nehalem, which is where Intel caught up with features like the on-die memory controller and started roughly a decade of unchallenged performance lead.

The TLB bug (Errata 298, doc 41322 if you really care - while the processor was attempting to set the A/D bits in a page table entry, an L2->L3 eviction of that PTE could occur) was one of a great many things wrong with that chip.

* A number of errata (not just 298) delayed full production, sapped performance, or negatively impacted idle power. Take a look at doc 41322, DR-BA step for many samples.

* It was late and didn't achieve performance targets; it missed clock rate targets and 2 MiB L3 was insufficient.

* Intel delivered a very compelling server part (Nehalem) during the lifecycle of family 10h.