You should be stripped of your damned title. You're not the hardware guy, you're the damned jester. The first basic law of science, matter cannot be created nor destroyed, it can only change forms. Hard drive space doesn't just disappear. As nmX.Memnoch already pointed out, nothing is lost, it's just a discrepancy in the methods of calculation. And before you complain and say "that what I said!", no, it's not what you said. If you know the correct answer but don't have the patience to take the time and effort to actually type out the correct and proper answer in your post, just don't post. There is absolutely nothing normal about the behaviour of your RAID array. I would suggest that you attempt the following to resolve your issue, in this order: - Update your BIOS to the latest version. - Re-install your chipset drivers - Make sure your Windows is up to date with all the latest updates - Re-install your RAID drivers (this usually requires you to download the latest F6 floppy disk, extracting it and manually updating the driver through Device Manager). DOH! Owned by the difference between 1024 and 1000. Now it makes since. Oh well, they are still a little over 300GB. Drivers it is. I hate updating nForce drivers. Last time I did, my vid card declined in performance and I got random errors with my built in Ethernet card.