ok, here's the reply from my friend, creator or FluidXP, (if you're a gamer you should be familiar with FluidXP).
It's lengthy but so is this thread so here goes...
"You can do a raid with a regular hard drive but depending on what type and
whose raid you are going to use it might not be a good idea.
Raid configurations are usually for some type of a server redundancy and
there is special things going on as far as what hdds are doing in a raid.
The "e" drives or enterprise drives are designed specifically for raid
configurations, desktop drives are not. I have seen many an operating
system take a dump because of using raid 1 on drives not specifically
designed for that as oppose to ones that were designed for that.
So basically in my opinion, for whatever its worth, you roll the dice when
doing raid with ntfs and not using enterprise rated drives. The
manufactures will not come out and say that you can't use these drives but
more and more of them, especially the good ones, are making specific drives for raided configurations.
It would probably be very prudent that if you are going to raid with a
regular drive to make sure that the other drive is identical and also make
sure that you have a backup of your important data.
The other thing that you will want to do is after you load your os and get
everything setup make a system restore point, might be good to also make a backup of your registry.
With software corruption, it does not matter whether your system was raided or not, you will be down because you will lose your os. If you have done a system restore point it will write that code on the hard drive and even if the hive gets corrupted which is what I usually see, you can restore the os from the dos shell in xp or vista."
I know he's talking about raid configuration, but that's a significant reason for the 'enterprise' rated drives.
Here's another reply after I told him about the concerns being raised here.
"Wow! That is interesting, Hitachi drives (formerly IBM) were and are still
some of the worst drives out there. I have used every drive out there and
based on what I have experienced in our servers which we build (10-20
monthly) Seagate makes the most reliable drives out there. You just have to make sure to get the right drive for the application. I kid you not, I have
seen more ibm and Hitachi drives fail from failure over the last 4 years
second only to Maxtor and now Maxtor is better because it is owned by
Seagate.
Well, this is usually how it goes in the computer industry, companies began
to compromise quality because they have built up a reputation. I have
watched pretty much all of them go the way of the dodo, now all of them are just driven by marketing and not on their product quality. If consumers
knew how bad the failure rates on some of these products were it would sure cause them to look real close at some other alternatives besides the ones in the spotlight all the time. But hey, HP and Dell are looking for me to become a warranty center so I guess that is a good thing. I can start a new motto "build the best and repair the rest"."
Integrity PC Systems & Technologies, Inc.
World Supplier of Fluid XP+ Products