the onboard LSI ROC chip, like most lowend LSI cards can take anywhere from 20 min to over a day to finish the background initialization task
create the array, leave that screen (don't reboot, just back out), and then go back after an hour or two, it may show progress. Some controllers abort initialization during a restart, so you'll never see progress if you don't leave it alone.
and benchmarking a drive array that is doing a background init is sure to give crazy results so don't do it