I am encountering a really weird problem on my WD Caviar Green HDD. Well first of all I have 2 HDDs on my Desktop, one 160GB Seagate holding my Win7 Ultimate x64 and the problematic one, WD 1.5 Caviar Green for storage purpose.

My problem is kinda weird, when I transfer files from my Seagate(C:) to my WD (D:) the speed is good (50-60MB/s). Then the problem arises when I transfer too "many" large files, the transfer speed would go straight down to kilobytes/s. Well after I cancelled the transfer and access my D:, even entering a folder requires loading for like 10 seconds.

Such problem not only arises when I am transferring files to my D:, it seems like my WD can't handle much activities. For instance, last time I installed my game on D: and I would face much lag after playing for some time. When the same game is installed on C: no problem arises.

Does anyone knows what is the problem?

P/S: There was one temporary solution that I used to tried. After the "situation" occurs, I tried to access as many folders on D: as I can and let it load, repeating such actions and giving it some time bring the D: back to speedy transfer. However, large transfers would causes the situation to happen again. Does it have something to do with cache whatsoever?