In a large scale real time simulation system, methods to reduce disk I/ O time at the ACP QIO I/ O interface as well as to improve the real time performance in a multiple processes environment, are introduced in this paper. 本文以一个大型实时仿真系统为背景,介绍了在ACP-QIO这一I/O层次减少磁盘I/O操作时间的诸多方法,以及在多进程环境下提高进程实时的一些措施。