Performing new sets on HDs ... 'hdparm'

[HostMaster of NullZone <hostmaster@nullzone.org>]

Hi there,

 i think its a trivial question for your all but im a bit new at Linux.

 How can i know if i can set better parametres with 'hdparm' utility on my 
ide drivers?
 How can i know if one of my mainboards support it? I know it support 
UDMA33 (just a PII 400).

and .. at least ..., may any tell me the exactly parametres to set ata 33 
to a ide drive?
I dont wanna to lost any data...

hmm btw, must i set special values over /dev/hdX or i must too over 
/dev/mdX if u have any raid softs?

U all can see im a bit lost...

Thanks by advance