dot net：快递版视觉工作室2008中的线程运行得太慢了？

i am running 12 threads .function which these threads are calling is not having any lock on some object.but still these threads are taking too much time.(16 minutes).each thread ially parsing a xml document which is running alright if run indiviually.is this problem because of some reason related max no threads provided by express edition or some blocking dn by express edition.i am running 12 threads .function which these t