The path length added to the overall system startup time path consists solely of the instructions contained in the MBB. The OS/2 Version 2.0 MBB is approximately 16KB in size, with about 50% being instructions and the remaining 50% being data and space for the boot table and error messages. Tests have shown no measurable increase in overall startup time, counting the time from POST exit to display of the selection menu, plus the time from the selection being entered to the appearance of the first OS/2 or DOS operating system message on the screen. Based on these tests, the impact of Boot Manager during boot time is considered negligible.
The MBB is loaded into memory during startup, and is later overwritten by the operating system boot record loaded from the logical drive from which the system is IPLed. Thus, no memory impact is realized when using Boot Manager. Memory requirements for the various operating systems participating in a Boot Manager environment do not change.