@grumble209 @gabrielesvelto Sun cheaped-out on the external cache pathway, using only parity protection rather than the ECC protection that direct competitors (HAL/Fujitsu) were using.

This made the US-II external cache vulnerable to environmental factors (alpha-particle emissions from common packaging materials).

@burnitdown @gabrielesvelto in the 70's, most issues were largely logic bugs, nowadays there are a larger proportion of timing/analogue issues.

@grumble209 @gabrielesvelto I remember that the UltraSPARC-II (Blackbird) CPU, over it's lifetime (and to date, to boot) only had a single errata, and that was an extremely unlikely timing issue, not a logic bug. Unfortunately, that overall goodness was offset by the widespread off-chip L2 cache issue circa y2k.