“I/O Pacing” reports how many times an I/O-intensive task was switched off an engine due to exceeding an I/O batch limit. Adaptive Server paces disk writes to keep from flooding the disk I/O subsystems during certain operations that need to perform large amounts of I/O.
Two examples are the checkpoint process and transaction commits that write a large number of log pages. The task is switched out and sleeps until the batch of writes completes and then wakes up and issues another batch.
By default, the number of writes per batch is set to 10. You may want to increase the number of writes per batch if:
You have a high-throughput, high-transaction environment with a large data cache
Your system is not I/O bound
Valid values are from 1 to 50. This command sets the number of writes per batch to 20:
dbcc tune (maxwritedes, 20)