Wait event

 Hi, I am getting I/O slave wait,db file sequential read,db file scattered read gc cr multi block request while session is gathering table's index statistics.
How I can speed up this process as it is taking very long time.
DB=10.2.0.4 RAC
OS=IBM AIX 5.3

EVENT                                                            TIME_WAITED
---------------------------------------------------------------- -----------
i/o slave wait                                                       4194035
db file scattered read                                               4012774
CPU used by this session                                             3437386
gc cr multi block request                                             291818
db file sequential read                                               138597
direct path read temp                                                  91712
db file parallel read                                                  30006
gc cr grant 2-way                                                       6608
row cache lock                                                          5699
gc current grant 2-way                                                  3824
gc current block 3-way                                                  1257

EVENT                                                            TIME_WAITED