The -cw and -c server options affect the initial cache allocation.
If you specify start_iq server options -cw and -c on the command line, the database server attempts the initial cache allocation as follows:
The AWE cache is no larger than the cache size specified by the -c option. If the value specified by the -c option is less than 2MB, AWE is not used.
The AWE cache is no larger than all available physical memory less 128MB.
The AWE cache is no smaller than 2MB. If this minimum amount of physical memory is not available, an AWE cache is not used.
When you specify the -cw option and do not specify the -c option, the database server attempts the initial cache allocation as follows:
The AWE cache uses 100% of all available memory except for 128MB that is left free for the operating system.
The AWE cache is no larger than the sum of the sizes of the main database files specified on the command line. Additional dbspaces apart from the main database files are not included in the calculation. If no files are specified, this value is zero.
The AWE cache is no smaller than 2MB. If this minimum amount of physical memory is not available, an AWE cache is not used.
When the server uses an AWE cache, the catalog cache page size is at least 4KB, and dynamic cache sizing is disabled. On 64-bit Windows platforms, the cache page size is at least 8KB.
For more information about dynamic cache sizing, see the -ch and -cl server options.