try to understand sga

oracle 10g on windows server 2003 r2.

We have set the following in the startup:

sga_max_size=2752M
SGA_TARGET=2752M
db_cache_size=512M
java_pool_size=128M
large_pool_size=628M
shared_pool_size=416M
streams_pool_size=128M
db_16k_cache_size=304M
PGA_AGGREGATE_TARGET=500M
db_block_size=8192
sort_area_size=40000000

SQL> select component, current_size from v$sga_dynamic_components;

COMPONENT                                                        CURRENT_SIZE
---------------------------------------------------------------- ------------
shared pool                                                         436207616
large pool                                                          662700032
java pool                                                           134217728
streams pool                                                        134217728
DEFAULT buffer cache                                               1174405120
KEEP buffer cache                                                           0
RECYCLE buffer cache                                                        0
DEFAULT 2K buffer cache                                                     0
DEFAULT 4K buffer cache                                                     0
DEFAULT 8K buffer cache                                                     0