Comment 35 for bug 1319457

However:

Sound card is eating about 5% of one CPU core:

Line from top:

 93 root -51 0 0 0 0 S 4,6 0,0 2:44.19 irq/16-

Fragment of /proc/interrupts

Is it normal for USB sound devices to generate such load?

           CPU0 CPU1 CPU2 CPU3
  0: 193 632 11469 650551 IO-APIC-edge timer
  1: 0 0 1 1 IO-APIC-edge i8042
  7: 1 0 0 0 IO-APIC-edge
  8: 0 0 0 0 IO-APIC-edge rtc0
  9: 0 0 0 0 IO-APIC-fasteoi acpi
 12: 1 0 0 4 IO-APIC-edge i8042
 14: 0 1 49 4226 IO-APIC-edge pata_amd
 15: 0 0 0 0 IO-APIC-edge pata_amd
 16: 4326115 10821 8863 214 IO-APIC-fasteoi , # btw, what comma does here instead of name?
 17: 0 0 0 0 IO-APIC-fasteoi eth0

The IRQ16 stops using CPU if USB sound card is disconnected. The card is connected to USB 3.0 PCI card identified as USB controller: Renesas Technology Corp. uPD720202 USB 3.0 Host Controller.