so I currently have one of those caviar blacks running in my machine right now. that is it, my only HDD in the computer. What I want to be able to do in the future(and I want to keep this computer as long as possible) is get other OS's set up along with Windows 7 when it retails. Would it be a good investment to purchase the Caviar Black right now? Or is it safe to stick with the one drive I have, partition it, and wait until SSD or VelociRaptors go down in price?
I've also heard of people getting a single small VR drive to install the OS and applications, and then getting a larger drive such as the caviar black to store files. I personally have never had a set-up like that before, always had OS on the same HDD as my files. I've also never used RAID before, but thought it might be a good idea as a way to keep my work safe.
(1) You should alwas back up your Data (operating system and programs can be re-installed). This is weather you use raid0 or 1, or not.
(2) If you get the 2nd WD drive, you can raid0 it and set a Raide strip for 100 Gigs (For Current operating system, a 2nd Raid0 stripe for 100 Gigs (for windows 7 and a raid0 strip for the remainer of your HD for your files/data. Operating system will "think" you have 3 HDD's . This is different than making 3 partitions on one drive.
(3) as to wait - Good question. SSDs will drop in price, it just WHEN. An SSD for operating system and a HHD for your Data makes the most sense. Don't forget you need a Back-up 2nd Hard drive (internal, or external) or use DVD-RWs.
Do not build a Raid-0, it's slower than a single disk nowadays, as I checked this week. At least for booting W2k and Xp. To launch a game with 100kB mean file size, as well. I expect a Raid-0 to be better on uncompressed pictures for instance.
The 640GB Caviar Black apparently has only 320GB per platter, leading to just 118MB/s throughput (see the user's measures at Newegg). Several competitors (Seagate, Samsung...) have 500GB per platter, giving a better throughput.
Use a GOOD Ssd, yes. My used X25E cost me some 200€ for 32GB (complement with an Hdd) and is every cent worth it. The most expensive part of the computer, but by far the most useful to accelerate it. But beware most Ssd are bad - worse that a 3.5" 7200rpm Hdd.