mchtower,
A lot of different things could cause this. Rather than trying to list them all, let me ask you a few questions.
What build are you running?
What type of system are you running it on (make and model)?
Is this a new drive just put in the system or the boot drive that has been running in it for a while?
If this is an older build and the system is set in AHCI mode this could be the problem. You can switch to compatible mode, test then switch back to AHCI
-Fred