Hi Henk,
i found maxdata works not correct in vdbench 50407, you can hava a try
sd=sd3,lun=d:\test\quick_vdbench_test3,size=40m,threads=1
wd=wd3,sd=sd3,xfersize=4k,readpct=0,seekpct=0
rd=rd1,wd=wd*,iorate=1k,elapsed=3000h,interval=1,maxdata=5
interval i/o MB/sec bytes read resp read write read write resp queue cpu% cpu%
rate 1024**2 i/o pct time resp resp max max stddev depth sys+u sys
11:13:35.168 1 521.0 2.04 4096 0.00 0.028 0.000 0.028 0.00 0.34 0.029 0.0 34.0 9.6
11:13:36.019 2 1004.0 3.92 4096 0.00 0.070 0.000 0.070 0.00 31.90 1.006 0.1 20.5 11.5
11:13:36.037 Reached maxdata=3.922m. rd=rd1 shutting down after next interval.
11:13:37.010 3 1020.0 3.98 4096 0.00 0.036 0.000 0.036 0.00 0.53 0.033 0.0 12.0 4.3
11:13:37.021 avg_2-3 1012.0 3.95 4096 0.00 0.052 0.000 0.052 0.00 31.90 0.709 0.1 16.2 7.9
11:13:37.295 localhost-0: 11:13:37.269 Total amount of key blocks read and validated: 0; key blocks marked in error: 0