Speed boost

What is speed boost?

Speed boost is a capability of System Recovery Boost that improves the recovery time of exploiting operating systems when running on a subcapacity CPC.

How does speed boost work?

If you are running on a subcapacity CPC, then while System Recovery Boost is active, z/OS requests that the CPC firmware increase the speed of CPs being used by the image to full capacity model speed for the duration of the boost. After the boost ends, the CPs being used by the image return to the subcapacity model speed. Since zIIPs always run at full speed, zIIP work will see no benefit from speed boost.

This increase applies only to the image being boosted; all other images not being boosted run at subcapacity model speed, and the CPC itself remains a subcapacity CPC. The capacity model number of the machine (described in System Recovery Boost basics) does not change because one or more of the images on the machine is experiencing a speed boost. If you are running on a subcapacity machine, IBM recommends activating Speed Boost, as all CP processes benefit.