AIX Version 4.3 Differences Guide

For AIX systems using AIX Version 3 Release 2 or greater needing to migrate to
AIX Version 4, the publication A Holistic Approach to AIX V4 Migration, Planning
Guide, SG24-4651, contains information about LPPs and AIX release
compatibility.
2.2 AIX 4.3 for 12-Way SMP Performance (4.3.1)
AIX Version 4.3 is tuned for 12 CPU SMP performance efficiency. This is a
continuation of the scalability evolution. Certain kernel areas identified by the AIX
performance team were investigated, tuned, and redesigned where necessary to
eliminate situations that could have impeded 12-way SMP performance.
2.3 32 GB Real Memory Support (4.3.2)
AIX now supports up to 32 GB of real memory and has been enabled to support
larger memory sizes as hardware grows in capacity.
CHRP (Common Hardware Reference Platform) is the system architecture base
for systems with large physical memory or any memory above 32-bit real
addresses. AIX will only support real memory addressing greater than 32-bits on
CHRP systems. Current AIX versions and their supported maximum memories
are provided in Table 5.
Table 5. Maximum Supported Memory Sizes
AIX Version
AIX 4.1.5
AIX 4.2.1
AIX 4.3.0
AIX 4.3.2
Maximum memory supported
2 GB
4 GB
16 GB
32 GB
2.4 Lock-Based Dumping
In AIX Version 4.1 and 4.2, the AIX dump routines always dumped the same data
areas. This generic policy meant that certain key data areas were kept out of
system dumps because their inclusion would greatly increase the size of the
dump. For AIX Version 4.3, dump routines have been added that gather
additional information for inclusion in a dump (based on the status of certain locks
or flags in the kernel) when the system dump is initiated.
If a lock protecting a structure is held at the time of the dump, then almost
certainly, that structure must have been in the process of being updated and
should be included in the dump. The primary area where this information is of use
is in the Virtual Memory Manager (VMM).
With these additional routines, the need to inconvenience customers with debug
kernels or reproduce the problem on test systems with the kernel debugger is
greatly reduced.
16 AIX Version 4.3 Differences Guide