Western Digital Caviar Blue 1TB - Slow transfer speeds.

Here is the drive I just bought from Newegg:
Western Digital Caviar Blue WD10EALX 1TB 7200 RPM SATA 6.0Gb/s 3.5

My issue with the drive above is that the drive speeds are extremely slow. If I try to transfer a big file, like 200MB+, it starts out transferring very fast then gradually comes to a standstill and the transfer rate drops to below 1mb/sec, sometimes transferring only in kilobytes, and the transfer never finishes as it's going too slow.

I also have another internal Caviar Blue set up with my OS on it. I was planning on using the 1TB drive as a drive to have my video and project files on while I edit. I have transferred files between my External Hard Drive and my OS internal drive and the speeds are fine.

Is there a problem with this drive or is there something I can do? I have the 1TB drive formatted as NTFS and as one primary partition. I've ended up formatting it about 5 times now. Thanks in advance.