Answer
For ArcSDE servers that have shared memory hosted in the database, per-process input/output statistics are not maintained unless you turn them on. Once turned on, they will be updated periodically at an interval you select.
To turn on the statistics, set the environment variable SDEPROCSTATS before starting the ArcSDE application server (giomgr). Set this environment variable to an integer indicating the minimum number of seconds between updates to the statistics. The default is -1, which tells the server to never update the statistics.
When there is a new request for statistics, the ArcSDE server checks whether the statistics (stored in the ArcSDE system table SDE.PROCESS_INFORMATION) have been updated within the last SDEPROCSTATS seconds. If not, the statistics are updated, posted and returned to the requester.