IRPCOUNT is a system parameter that sets the number of preallocated intermediate request packets. Each packet requires 160 bytes of permanently resident memory. If IRPCOUNT is too large, physical memory is wasted. If IRPCOUNT is too small, the system increases its value automatically, as needed, to permit proper performance. However, the system cannot increase IRPCOUNT beyond the value of IRPCOUNTV.
Allowing this growth causes a physical memory penalty. If IRPCOUNT is underconfigured, the penalty is 4 percent of physical memory from the configured value to the actual value on the running system.
You can use the DCL command SHOW MEMORY/POOL/FULL to determine IRPCOUNT usage.