Time to boot up the system (mm:ss) Indigo2 R10000SC/195 1MB: 1:07 Indy R4400SC/200 1MB: 1:13 Indigo2 R4400SC/250 2MB: 1:25 Indy R5000SC/180 512K: 1:28 Indy R5000PC/150: 1:38 Indy R4600PC/133: 1:38 Indy R4600PC/100: 1:38 O2 R5000SC/200 1MB: 1:54 Table 5: IRIX 6.5 Bootup Times
For some reason, O2 has always taken longer to bootup than older systems, probably due to the more complex I/O arhcitecture, and thus likely more startup initialisation signals, etc.
Note that because a totally default installation includes a deliberate 10 second delay during bootup while the message concerning 'standalone network mode' is displayed, this 10 seconds is not included in the above times, ie. the /etc/init.d/network file has been edited to change the MSGTIME value to 0. Likewise, for updated versions of 6.5.x, it is a good idea to turn off ESP and any other services not being used; such actions can shorten bootup times by as much as 2 minutes.
Here is the table for IRIX 6.2:
Time to boot up the system (mm:ss) Indy R4400SC/200 1MB: 1:07 Indy R4600PC/133: 1:22 Indy R4600PC/100: 1:22 Indigo2 R4400SC/250 2MB: 1:24 Table 5b: IRIX 6.2 Bootup Times
Notice that in both cases the Indigo2 R4400SC/250 takes slightly longer than the R4400SC/200 Indy - I expect this is because the Indigo2 has a larger number of internal checks and initialisations to do since it has more internal hardware systems than Indy.