which rc file for hdparm commands?

["Gladimir" <listmgr@san.rr.com>]

I am slowly working my way through the HOWTO files on the linux
documentation site, beginning with Config-HOWTO, which recommends starting
with my kernel and hard disk performance.

The problem is that section 2.6 recommends adding hdparm commands to the
following file:
  /etc/rc.d/rc.sysinit

Of course, I have no such file on my system, and it would be futile to visit
all 7 of the rc#.d directories and grep for the hdparm command because that
command was not on my system until a few moments ago.

Would the hdparm command add any performance (i.e. 32 bit access) to a 1997
pentium system with 1.5GB hard drive?  If so, where is the appropriate place
to enter hdparm commands?

Thanks in advance for your help.

- g