This reports the percentage of the card's packet-processing CPU busy specifically on foreground, real-time, higher-priority tasks, as distinct from cardCpuUtil's overall figure. Watching this separately from overall CPU utilization lets an admin tell whether high CPU load is coming from time-critical packet forwarding itself versus background or maintenance tasks, which points to different remediation depending on which is elevated. For example, cardCpuFgUtil running near 100 percent while overall cardCpuUtil is only moderately elevated suggests the real-time forwarding path itself is the bottleneck, not background diagnostics or housekeeping tasks.