PCIe/CXL Deep Dive · All levels
PCIe/CXL Metrics Reference
Core metrics for latency quality, command efficiency, margin health, and field reliability.
Core metric families
QoS: p50/p95/p99 latency, jitter, and class fairness.
Efficiency: effective TLP bandwidth, credit stall ratio, completion latency.
Capacity pressure: queue age distribution and blocked-cycle share.
Margin: eye width/height, Vref drift, retrain frequency, byte-lane outliers.
Reliability: CE/UE trends, scrub impact, rowhammer alert rates.
diagram
BEFORE/AFTER TREND - PCIe/CXL Closure
metric before after fix
------------ -------- ---------
bandwidth 42 GB/s 48 GB/s
p99 latency 18 us 9 us
error rate 12/hr 0/hr