The hard drive is used to do BitTorrent with µTorrent. Recently uTorrent began to report there is a "I/O Device error". When I use HD Tune to test it, it turns out the transfer rate is only 16 MB/sec. At the same time, I have a similar hard drive tested, it rates as 120 MB/sec. They are both 7200 RPM desktop hard drives.
I used CHKDSK to fix it, but the rate didn't change.
Is this a symptom of hard drive failure? Should I backup the content on the disk ASAP or is there any other tool can fix it or diagnosis it?`
Those are screenshots, from the pictures, everything looks OK except transfer rate(?):