Desktop freezes up when accessing "D:" Drive

Whenever I start-up my computer and access my storage HDD (D: Drive), it freezes up my entire desktop for about 15 seconds. After the desktop unfreezes everything goes back to normal. (While the desktop is frozen my taskbar and every program is responsive. Just the shortcuts, programs & right clicking on desktop stops in it's tracks.) After the initial 15 seconds of freezing I can access the HDD without any problems or stalling. Freezing starts back up after I shutdown and start back up, log out and log back in, or restarting the computer.

This has been an ongoing issue for at least a month now and it's really agitating . I have tried moving the HDD to every SATA port; Tried updating HDD Driver through Device Manager; Went into Advanced Power Options and went to "Hard Disk -> Turn off hard disk after -> Never"; Also went into BIOS and looked to see if any options would resolve the problem. I use two Kingston HyperX SSD's in RAID0 for my OS (C: Drive), which is Windows 8.1 64-bit. Here's the run down of my computer components:

HDD: Seagate ST31000528AS SCSI 1TB for storage
CPU: AMD FX-8150 (Stock Clocked @ 3900.70 MHz)
Motherboard: Sabertooth 990FX R2.0
GPU: Two 7970's Crossfire'd (Both Stock Clocked @ 925 MHz)
RAM: 16GB
PSU: 1200 Watts
BIOS: 2301

Any advice or insight would be greatly appreciated.

P.S. My HDD doesn't seem to be failing as it never slows down - except for the first 15 seconds I access the drive. I defrag it every two weeks.

You might need to run SeaTools for Windows | Seagate to check possible errors and SMART info of your drive.