So why does my computer do this?

I’d frequently leave the computer on for a week, turning it off only on the weekends. During the week, I usually have a bunch of windows opened to Word, IE, different folders, etc.

I noticed that at the end of the day on Friday, after I’ve had a particularly large word file opened for a week, it takes forever to close. I can hear the hard drive spinning as the computer’s trying to do that. Why does that happen?

With IE its even more pronounced. If I have a random webpage opened, like the Dope, and the next morning I try to surf the net, it takes forever and I can hear the hard drive spinning too. Why does it become slow like that? It usually takes 10-15 mins for the speed to get back to normal and for the sound to disappear.

FYI, I’m on a typical Windows XP machine. A little old, maybe 2007ish.

because after that much use and that runtime, more stuff has been run that could fit in physical RAM. so, some of your data was written to the pagefile for later retrieval, and code was dumped from memory and has to be reloaded from the hard drive.

in my experience, things like this happen when you’ve had a lot of stuff open and, say, a virus scanner decides to do a full scan. in doing that, it’s doing a lot of disk I/O and reading and writing from system memory. therefore stuff you’ve used the least recently has to be cleared from RAM so the scanner has enough memory to do its work.

I think it’s just swapping memory segments to disk and back. Windows allows programs to use more memory than is physically installed on the motherboard. If a 30-megabyte document is open in Word but you haven’t looked at the last 100 pages for a while, Windows will often reclaim the corresponding area of memory by swapping out the contents to disk. This allows Windows to allocate this memory to other programs, to the disk cache, etc.

When you try to close Word, it may need to look at the whole document one last time (to update the word count, for instance). Windows will detect that the program is trying to access some swapped-out parts of its memory, and will quickly read them back and make them available again – probably swapping out some other program’s stuff to make room.

The same thing happens when you close IE. It, too, needs to access all its tabs in order to close them.

If both programs are trying to close at the same time, they can end up competing for the same limited memory resource. So you get lots of swapping.

The usual recipe to limit swapping is to add more physical memory to the computer. Windows XP can handle up to 3 GB of physical memory, if I remember correctly.

If adding memory is not an option, you can try to close only one program at a time (wait until Word has finished closing, then close IE). You’ll probably save a little bit of time this way.

also, just to add to what Heracles said, all desktop OSes do this nowadays; they may call it “swap” in the case of Linux and other *nixes, and I’m not sure what Mac OS X calls it, but all OSes with a real virtual memory system work similarly.

Thanks. Now I know.

FWIW, physical memory limit on XP is 4GB according to Microsoft.