I last reformatted my Hard Drive after installing a second Seagate 160 GB SATA HDD and setting the Raid for "Striped mode". Whilst this should double your transfer rate (from 150 to 300 Gbits/sec.), in effect doesn't, but produces a significant transfer speed improvement and results in a more stable transfer rate. RAID can be set up as "mirrored" or "striped". In the former case it provides a complete mirror of HDD 1 on HDD 2. In the latter case, data is "shared" across the drives, giving an effective increase in data read and write.
My system is composed of an ABit NF7-S motherboard, an AMD Barton 2600+ clocked at 2.35GHz, and 512 MB of 3200 DDR RAM, Nvidia 5700U Ultra Video card, and an Audigy 2 Sound card.
When the SATA and RAID drivers are installed during Windows XP installation, XP reports that I have one (1) 300 GB HDD. This is expected using dual drives in Striped RAID mode.
I always partition my HDDs into 3 or 4 partitions. I always created a System partition (10 to 20 GB) to hold the operating system, drivers, and routine software such as Office, Dreamweaver,general utilites, etc.
In this case, I have a 20GB front partition, 2 x 117GB partitions (labelled Data and Entertainment), and the remainer (44GB) as a Utilities or backup drive.
This means if I have a software crash, I can do a clean reinstall of XP on my front partition without data loss, and I can backup my C drive on my Utilities drive using, in my case, Ghost 2003. I also load the contents of routinely used programs in folders on this drive, and install Office, etc. from there, rather than the CD. This has the advantage of not having to resort to using my original CDs for any extras for Office etc. If Office requires any extra files, it will automatically go to E drive to find them, rather than asking for the CD. I also keep my motherboard, sound and video card drivers, and Windows and Office Updates and patches in appropriate folders on this drive.
Once set up, this makes a complete system reinstall fast and painless.
I also have the option of reimaging my C drive from the image on my E drive, or the basic one I keep on my 2003 Server. I back up my "critical" data in 4.5GB blocks with my DVD burner, as well as my movies, mp3 files etc.
I defrag my HDDs every night, and run Easycleaner regularly to clean up my temp files and unlinked registry entries Windows loves to produce in abundance.
I find this to be a reliable and very satisfactory system for managing my PC.