Read this thread if you own a Western Digital "Green" HDD.
Some time ago, I noticed my new netbook's disk regularly lagged when opening tabs on my browser, or playing games (particularly, when Warzone 2100 changed to another music track). These pauses lasted 2-3 seconds and occurred several times a day, which made them highly frustrating. I researched all the possible causes, but no fixes worked until I stumbled upon the following information.
The "Green" line of drives has an idle timeout (called "Idle3" by Western Digital), which parks their heads when reached. This is supposed to save energy by not making the head work if it's not required. The problem is, said timer is set to a very low value by default, and the head doesn't instantaneously return to operation when work is required once again; there's a delay of a few seconds, which causes the aforementioned freezes. So much zigzagging also wears it out. The disk head becomes a possible point of failure after approximately 600000 parkings, of which an average user burns 40000 a month.
Unless you leave your computer idle for long periods, or only use your WD drive(s) for data storage, the power saving achieved in this manner is rather negligible, and thus not worth the constant freezing and reduced lifespan.
You can find many sources for the above information by looking up "Western Digital" plus "idle", "Load Cycle Count" or "APM" in your favorite search engine, including an official support article where the company suggests spacing automated writes to avoid this :rolling_eyes:
However, there is a solution. According what I've read and then converted into personal experience, there are three possible ways to solve this problem, depending on your model: using an official DOS-based tool to disable Idle3, using several unofficial programs available to disable APM, or both.
The DOS tool is called WDIDLE3 and can be downloaded here. If you need a FreeDOS disk image with the program included (you can't run it from Windows or DOSBox), to write on a floppy or use with the bootable flashdrive creator of your choice, let me know. Executing WDIDLE3.EXE /R displays the current idle timeout. Using the /D switch turns it off.
If that's not enough to stop the freezes, you need to also turn off Advanced Power Management. There are many free tools to do that, the easiest I've used being HDDScan. However, there's yet another pitfall. Your particular model might not store the setting permanently, resetting the APM value when power cycled, meaning you'd have to do this after every cold boot. Thankfully, there's a program called quietHDD that stays resident and changes the setting whenever necessary. I personally used a Windows port of hdparm, scheduled to run on startup and whenever the computer resumes from hibernation (that's event ID 1, source Kernel-General, log System).
After doing all this, the clicks should be gone, and the Load Cycle Count SMART attribute won't go up a few hundred times per day. :happy: