excessive number of db writer

Hi

I have been suggested by some Oracle Consultant to set 20 Database Writer in a 12 CPU HP-UX Server.

Does anyone know what are the side effects of having excessive DBWR? I detected a higher CPU usage (between, 1% to 2%) not sure if its due to the number of Database Writer. Because when I increased the number of DBWR at init.ora I also changed these parameters

_row_cache_cursors = 60
_kgl_latch_count = 59
_kghdsidx_count = 4

statistics_level = basic

again suugested by this guy.

TIA Alex

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