RAID is a poor idea unless you really need it. With very mismatched drive sizes you will end up with the larger drive having one Partition involved in a RAID array, plus a bunch of empty space you need to use to create another Partition for data storage. Then there's the possibility that your older drive will fail much sooner than the new one, ruining your RADI array and (in the case of RAID0) losing all your data.
Better choice, I think, is to migrate everything from old to new drive. If you don't have it already, go to the WDC website and download (free) and install their Acronis True Image WD Edition software. Run it to clone old to new, making the new drive use ALL of the 640 GB, not just duplicate the old 160 GB Partition. Make sure it is set as bootable (if you have any choice on this) and uses the NTFS file system. When you're done cloning, my practice is to disconnect the SATA data cable from the old drive and plug that into the new drive (removing the new drive's temporary data cable). That way the new drive is now connected to the SAME SATA port that always had your boot drive on it. I'd leave the old SATA drive completely disconnected for now (can leave mounted inside the case) as a good backup (up to the cloning time) you can use if the new system has a problem. Once you're happy the new drive is doing everything right, reconnect the old SATA and destroy all its old Partitions. Then create a new Primary Partition (all of disk, NOT bootable), format is to NTFS, and use it as a data storage unit.
Another possibility: buy an external drive enclosure and mount the old drive in it. Use it to make periodic backups of your main drive, then disconnect it when not in use so it is isolated from the computer system and from electrical supplies, including any bad surges or lightning strikes. You can even move it offsite when not making backups. One of the easiest ways to make that backup (if it will fit) is to use that same Acronis True Image WD Edition software to clone the main drive to the external drive - then you get everything at one shot.
In choosing an external enclosure, make sure you get one with a SATA II internal interface to the drive itself. For the interface to your comp, check what your comp has for this. If you have eSATA it is the fastest commonly in use. Firewire 400 (aka IEEE 1394a) is about the same. USB2 is a little slower, but is found almost everywhere. Mine has both USB2 and eSATA.
I agree with tanderskey, especially the last idea. The pagefile gets used a lot if your system RAM is not huge. So I always put mine on another drive - NOT the C: drive with its OS and applications, etc - so pagefile access does not compete with other operations and slow thing down.
My plan was to simply migrate the old drive info to the new one (as you suggested, Paperdoc).
I thought I'd check with more knowledgable folk, to see if there was a better option (performance, etc).
BTW, I've never actually partitioned a drive before, just kept the whole thing as a C: drive. Are there any significant benefits in partitioning, or just keep everything "under one roof" (C: drive)?
Thanks again for your help.
Well, if you partition (divide) your drive into C: and D: or more, you can put your important documents and files on the other partition for safe keeping. For example, if your computer was hit with a virus, and you couldn't boot up your computer, and there was nothing you could do about it, you're only choice would be to format your C: drive and reinstall Windows. As a result, everything on the C: drive would be lost. However, since you moved all of your important stuff to your D: drive, all of that is still safe.
Creating partitions is also good for organizing. This is how I have my computer set up:
Suggest you get BlacX and stick your old HD in their as a backup drive.
That leaves you with just one drive to worry about. Here's my thoughts on single drive systems.
1. Make and OS drive for the OS only; yes I realize that many programs wanna put stuff there but take control of that to the best you can and always do custom installs. Why ? It's a lot easier to replace a fudged OS when it's 32 GB's rather than 30 times that.
2. Next partition is D for page file and temp files. Make this partition FAT32 to reduce overhead. No need for the safety of NTFS for tempfiles. Why ? Your page file and temp files are the most active area of the disk. You want them unfragmented and on the outer edge of the disk where it's twice as fast as the inner edge or you want them fragged all over the place getting nearer and nearer to the slow edge of ya platters ?
3. Now I do a game partition, Lets face it what needs more speed game sor programs.
4. Next comes Programs partition
5. Next Data Partition
6. Backup partiiton just for config files, mozbackup and things like that.
If ya not sure what drive to pick for what purpose, see this post