This Gauge32 is the high-water mark for inter-socket memory-mirroring errors on this CPU recorded during the trailing 1-day window, the day's peak error rate rather than its current level. An admin uses 1DayH to know how severe mirroring errors got on this processor at their worst point in the last day, even if the situation has since improved. For example, a large 1DayH value with a much smaller current 1Day rate would suggest a transient event, such as a brief thermal excursion, rather than an ongoing hardware fault.