I have a friend that has a Dell Precision T7500. It has a PERC 6i RAID card with two Seagate 1.5TB SATA drives (plain cheap SATA, not SAS drives) in a RAID 1 config. He said his PC was running really slow and some programs would crash in Windows. After checking it out for a while I thought it felt like it was a failing HD as I've seen enough of them to just have a feeling by the way it acts. Checked the event log and saw where numerous programs were crashing and services were timing out and closing. When you used the PC it would actually boot up and run ok but for 30 seconds or so it'd run fine then explorer/whatever program would stop responding for a minute or so. Anyways I'm thinking bad HD and didn't even realize it was a RAID array at first. So I go into the PERC 6i's config and it shows SMART status as OK with no errors (both drives). So I kept working on the PC for another two hours trying to find something else wrong like bad memory or problems with Windows itself but it still all points to a bad HD. I've replaced a LOT of hard drives, even drives in a RAID 1 array but its usually cut and dry easy to diagnose and has SMART errors. I'm not familiar with the PERC 6i... can I disconnect the drives from the controller, hook them up to my PC one at time and run diags? So far every (free) diagnostic program I've run doesn't support RAID so it shows the logical drive not the individual ones. I considered taking drive 0 offline, or just unhooking it, and letting it boot up on the second drive and see if there's a difference. Should be pretty easy to tell as even the Windows 7 "Welcome" screen takes 2 minutes to load and this is on a dual Xeon with 12GB RAM. Of course any filesystem corruption problems would be on the mirrored drive but if it was "freezing" because it was hitting bad sectors on the drive 0 I would think this would fix that. And if I pull drive 0 offline on this PERC card, will hooking it back up be a problem? I haven't messed with PERC cards enough to remember, it's been a year or so since I've worked with one that had failing drives... or at least drives that had data that I would be worried about losing.