Creating a RAID after installing OS

So, here's the situation. I just built my new PC, and I have a 64GB SSD and a 1TB HDD. I set them both up AHCI and installed my OS to the SSD, along with all my most commonly used programs. The HDD was going to be for media storage. But it seems that the HDD I purchased is a dud, so I have to return it.

Now my question is this:

If in place of the 1TB HDD, I buy 2 500GB HDD, will I be able to set those up in a RAID 1 array without having to reformat the SSD? I would like the comfort of knowing that my media is always backed up.

If such a set up is possible, what's the best way to go about doing it? Can I just go into the BIOS and change from AHCI to RAID, or will that affect my SSD? Is there a way to do this from within Windows 7, or some software that will aide me?
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  1. You should be able to setup Raid 1 without any issues. Most likely you would just need to enable raid, then switch to the raid controller during bootup (there is a usually a key combo like Alt+G) or something like that, then create the array from within the Raid controller bios. Just make sure you are selecting the correct drives when creating the array.

    The specifics all depend on the mb/raid controller you have.
  2. As long as you don't have data you want to preserve on a HDD are not affecting the OS on the SSD, you should be good.

    You will probably have to boot into some RAID menu before the OS boots to configure it. Once in the OS, it will appear as one drive.
  3. One more question:

    Is RAID1 slower than a standard AHCI configuration? I understand that, by its nature, it is slower than RAID0, but will I see performance differences in setting up a RAID1 versus having just the stand alone drives that I back up manually?
  4. Depending on your raid controller Raid 1 would likely be very close to a single drive. If you are just using it for storage you probably wouldn't notice a difference either way.
  5. Techincally RAID 1 is slower because it is writing the data to two disks, but you'll likely not see too much of a difference.
  6. RAID 1 installation should go smoothly! (Famous last words - :) )

    Your motherboard manual will explain how to get into the RAID BIOS during start-up. Once you are in, make absolutely sure that you pick the correct disks for the RAID setup (I made an error the first time around).

    RAID is normally setup after installation of the OS.

    Select 1 TB disks for RAID 1 - two 1 TB disks in RAID 1 have a total capacity of 1 TB not 2 TBs. http://www.newegg.com/Product/Product.aspx?Item=N82E16822136533

    In addition to this, frequent back-ups are recommended. RAID is not a substitute for back-up.

    BTW, is this new computer on an acc. dep. schedule or straight line?
  7. What MB?? and what controller is the SSD on??

    May have a problem, the SSD may not boot into windows if the SSD is on the same controller as the HDD and you change the controller to raid from AHCI - Different controller.

    To verify is very simple. Change the controller to raid and if you can no problem!!
    If not. Change controller back to AHCI.


    If NO to above then, If Available put the HDDs on a different controller and set to raid then create Raid Volume.

    Else, yes you will need to reinstall windows.
  8. RAID 1 adds redundancy, but is not a replacement for a full backup of the system, by creating a drive image.
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