Indecisive hard drive


My HDD is set to spin down after like 20 minutes of inactivity. However, on the few occasions I have been sitting at the G5 when it does this, I hear:

PHEWWwww... (that's the spin down)
(a little time goes by)
(pheeeWWW-CHUNK) (now it spun up again and engaged)

Then it spins down again. Then spins up. The computer is basically not doing anything when this happens, as far as running processes. What's the deal? Do I need a firmware update or something? The Mac is not on the 'Net so it wouldn't be easy to update. 1.6GHz G5, running OS X 10.4.0 (but it happened under 10.3.x too).
There are ALWAYS processes running, even when you're logged out of the computer. The only sure-fire way to make sure that absolutely no processes are running is to turn the computer off. Even with all applications closed and the computer sitting at the login screen, there are about 40 or more system processes that are ALWAYS active and "processing."

Is this the factory drive that shipped with the computer, or a 3rd party drive you installed yourself?
Like ElDiablo said, there are always processes running. And when there are processes running, OS X will very likely be swapping data in and out of its virtual memory files. It happens to me all the time, to the point where my HD never spins down in Tiger. I can watch Activity Monitor and see it keep paging memory in and out as I do nothing. Painful.

So my diagnosis is that you need more RAM (who doesn't, with Tiger?). Just a guess, thoughm really. You should take a look at Activity Monitor and see if there are any suspicious-looking invisible processes running. Anything owned by root is probably standard system stuff (unless your security has been seriously compromised).
To answer ElDiablo, it's the factory drive. But it's reassuring to hear that I'm not the only one who has this problem. I guess I'm still used to the Classic OS, which basically never used the HD unless you were doing something. Oh well. I don't think there are any suspicious processes running.

I'm thinking of getting more RAM anyway, so maybe it will help. We'll see.