nv_sata performance issues

[Kurt Heine]

Hello all.  I am having performance issues with SATA drives and I am wondering where I may look to figuring out what is going on and maybe tuning the discs to increase performance.

I am running a two servers a production and a test server .  One server is the older HP DL145 G1 running PATA using 2 drives in software RAID-1 and the other is a newer HP DL145 G2 running SATA hardware RAID-1.  Each server has 4GB of memory and the newer G2 has a second processor.  The old server is running RHEL3 ES U5 and the newer one is running RHEL4 ES U1.

What I am noticing is when the drives are under load on the newer G2 server then the system becomes rather sluggish and preformance is extremely slow because of being io bound.

I have included the dmesg of the hardware for the rhel4 based G2 server and the rhel3 based G1 server.

Where is a good place to start looking and seeing where I can tune (if possible) to get better performance?

Regards,
  Kurt Heine