Thanks for looking @andreas-doehler
here is the load of our server
Cpu0 : 23.6%us, 15.2%sy, 0.0%ni, 47.1%id, 13.8%wa, 0.0%hi, 0.3%si, 0.0%st
Cpu1 : 25.0%us, 11.0%sy, 0.0%ni, 62.7%id, 0.7%wa, 0.0%hi, 0.7%si, 0.0%st
Cpu2 : 18.0%us, 10.7%sy, 0.0%ni, 55.0%id, 16.0%wa, 0.0%hi, 0.3%si, 0.0%st
Cpu3 : 26.0%us, 13.2%sy, 0.0%ni, 52.0%id, 8.4%wa, 0.0%hi, 0.3%si, 0.0%st
Cpu4 : 30.0%us, 12.1%sy, 0.0%ni, 57.6%id, 0.0%wa, 0.0%hi, 0.3%si, 0.0%st
Cpu5 : 17.9%us, 11.0%sy, 0.0%ni, 70.8%id, 0.0%wa, 0.0%hi, 0.3%si, 0.0%st
Cpu6 : 24.2%us, 11.7%sy, 0.0%ni, 60.7%id, 3.4%wa, 0.0%hi, 0.0%si, 0.0%st
Cpu7 : 22.7%us, 12.4%sy, 0.0%ni, 64.5%id, 0.0%wa, 0.0%hi, 0.3%si, 0.0%st
Mem: 16431516k total, 15154716k used, 1276800k free, 222644k buffers
Swap: 8380412k total, 0k used, 8380412k free, 3866884k cached
00:00:05 runq-sz plist-sz ldavg-1 ldavg-5 ldavg-15
00:10:02 12 496 0.37 0.74 0.85
00:20:02 8 480 0.41 0.69 0.80
00:30:02 24 516 0.48 0.59 0.71
00:40:02 11 484 0.94 0.80 0.77
00:50:01 12 567 0.62 0.70 0.74
01:00:02 14 556 0.95 0.73 0.73
01:10:02 9 484 0.88 0.98 0.87
01:20:02 22 585 1.91 1.51 1.12
01:30:01 16 565 1.29 1.34 1.26
01:40:01 37 550 1.23 1.17 1.20
01:50:01 8 541 0.93 1.11 1.17
02:00:01 5 541 1.29 1.03 1.08
02:10:03 30 589 0.63 0.84 0.98
02:20:01 7 530 0.85 0.75 0.85
02:30:02 7 510 0.71 0.80 0.84
02:40:02 50 580 0.64 0.74 0.81
02:50:01 11 545 0.61 0.66 0.74
03:00:01 3 535 0.80 0.68 0.71
03:10:02 9 547 0.62 0.71 0.75
03:20:01 12 539 0.75 0.80 0.78
03:30:02 9 521 0.62 0.75 0.79
03:40:01 28 529 0.68 0.80 0.80
03:50:02 48 645 0.71 0.88 0.88
04:00:01 8 551 0.56 0.70 0.79
04:10:02 3 557 0.55 0.60 0.71
04:20:02 10 561 0.96 0.76 0.72
04:30:02 67 595 0.38 0.54 0.63
04:40:03 15 598 0.87 0.71 0.66
04:50:03 49 584 0.64 0.67 0.68
05:00:02 14 598 0.67 0.69 0.69
05:10:03 51 575 0.23 0.53 0.63
05:20:03 29 630 0.55 0.68 0.68
05:30:02 8 597 1.16 0.87 0.75
05:40:02 15 593 0.48 0.57 0.64
05:50:02 10 551 0.67 0.63 0.66
06:00:02 7 563 0.47 0.62 0.65
Average: 19 555 0.75 0.79 0.81