Text-based stimulus: A privacy-first audit table titled Aggregate Device Metrics. Rows: Memory 99%, Page faults high, CPU 18%, Disk 12%, Network latency 30 ms. It also includes footer text: No browsing histories collected. An administrator wants to collect detailed browsing histories to explain slow devices, but the existing privacy-first metrics already show memory 99%, high page faults, CPU 18%, disk 12%, and network 30 ms. Which bottleneck is supported by the evidence?