We have about 1500 concurrent calls on the server. And, the CPU usage is shown below: 02:06:46 AM CPU %user %nice %sys %iowait %irq %soft %steal %idle intr/s 02:06:46 AM all 0.06 0.00 0.03 0.44 0.00 0.00 0.00 99.47 1028.25 02:06:46 AM 0 0.08 0.03 0.03 0.01 0.00 0.01 0.00 99.84 1007.07 02:06:46 AM 1 0.06 0.00 0.02 0.01 0.00 0.00 0.00 99.91 0.00 02:06:46 AM 2 0.07 0.00 0.08 3.49 0.02 0.00 0.00 96.34 21.18 02:06:46 AM 3 0.05 0.00 0.01 0.01 0.00 0.00 0.00 99.94 0.00 02:06:46 AM 4 0.04 0.00 0.02 0.00 0.00 0.00 0.00 99.93 0.00 02:06:46 AM 5 0.05 0.00 0.02 0.00 0.00 0.00 0.00 99.92 0.00 02:06:46 AM 6 0.05 0.00 0.02 0.02 0.00 0.00 0.00 99.91 0.00 02:06:46 AM 7 0.05 0.00 0.02 0.01 0.00 0.00 0.00 99.93 0.00 1) I am wondering whether it is normal that every time when i checked, only CPU 2 always have the highest %iowait (in this case 3.49%). 2) Shoudn't it spread out and balance them to utilize all CPUs evenly? Thank you.