kimnjerry said:
Elliott:
Thanks for your time. I'm not technically oriented, so I don't
understand much of what you've said. Forgive me if I'm getting too
basic, but, if you have the time:
Heh! I asked for that. Here we go!!
* What do you mean by "top?"
It is one of those unixy command line things. It displays a few
interesting tidbits about the internal state of your system.
First bring up a terminal window. Its in
Applications->Utilities->terminal
Type the magic incantation 'top -u -s5 10' right after where it says
something like
Welcome to Darwin!
Whatever:~ Jerry$
and press return.
You will then get a display like this:
Processes: 70 total, 2 running, 68 sleeping... 192 threads 22:12:41
Load Avg:0.53, 0.25, 0.12 CPU usage: 5.1% user, 9.4% sys, 85.5% idle
SharedLibs: num =123, resident = 49.2M code, 4.04M data, 19.1M LinkEdit
MemRegions: num = 11626, resident = 197M + 14.2M private, 234M shared
PhysMem: 90.9M wired, 295M active, 358M inactive, 745M used, 22.6M free
VM: 6.21G + 83.6M 95680(0) pageins, 21698(0) pageouts
PID COMMAND %CPU TIME #TH #PRTS #MREGS RPRVT RSHRD RSIZE VSIZE
1718 top 5.4% 0:01.13 1 16 25 304K 492K 704K 27.1M
1710 Terminal 2.4% 0:04.28 3 66 190 2.26M+ 34.6M+ 8.60M+
and another 8 lines that change every 5 seconds too.
· What are pageouts and pageins?
OK you see them in the sample above?
A pagein happens when you start running a program, or even start
running a bit of it that has not yet been exercised, and when its data
is paged back in after being paged out (see later) What is happening is
that pages of memory are being read from the disk where a copy of the
program has been kept.
Sometimes there is not enough memory free. In that case, bits of
another program that are not currently being used, and bits and pieces
of the data it is operating on are paged out to make room. The data is
squirreled away in special files called swap files.
Later, when that stuff is needed again, it is paged back in.
So if the count of all the pageouts and pageins keeps going up, it
means that you do not have enough memory in your machine, and the
operating system is 'swapping' too heavily.
The system displays that spinning beachball while that is goingn on.
Don't worry about large numbers in there as long as they are not going
up by a few hundred every five seconds.
The OS is quite sly and efficient about swapping stuff in and out, but
if the sum of all the programs and data is far greater than the memory
to hold it all, the swap files grow bigger and bigger and there are
more and more of them created over time. Because the order in which the
pageouts occur depends on all sorts of random events, and where the
data gets swapped to depends on where the system can find a clear bit
of swapfile space, over time, the swapfiles become a bit of a mess.
· When you say "How long is it since you last logged out?" Are you
talking about shutting down the computer?
When a program is quit, its swap file space is no longer needed, yet
there may be fragments of many other programs sharing a particular swap
file, so it may take a long time for a particular swap file to become
completely unused, when the system will delete it.
· I don't understand what "swap files" are...or how to untangle them.
OK, I think I managed to explain swap files already.
Untangling happens when you log out - all your programs will quit at
once and swap files will magically evaporate, because when all your
programs will quit at once, complete swap files will become unused. The
swap files will be replaced by clean fresh ones when next you log in
and start lots of programs up again and overfill your memory.
(If you do not know what log in and log out are, that is because you
have set your system up to automatically log you in. Otherwise you will
see a panel asking for your name and password before the machine will
let you do anything to it.)
· When you say "reboot the machine once a month," I suspect that's
not "restart," but another operation.
Sorry, the jargon crept in there. It is the same thing.
If you turn the machine off when you finish each day, that should keep
the swapfiles tidy, unless you are very short of memory.
I like to leave my Powerbook running for months on end, simply because
I like how fast it wakes from sleep, with everything as I left it. For
me, with 768MB of memory and fairly modest numbers of bloated sotware
active at any time, logging out every few days keeps it tidy enough.
(You ought to see my desk - that's something else entirely.)
If you have the time to respond, I'd appreciate it. If it's too much
work to explain it, I understand.
PS - another trick to keep your machine in good shape is to leave it
switched on overnight every now and then. All kinds of magic cleanups
schedule themselves in the dead of night.
I think that your 512MB, shared among two processors is a bit on the
light side. You will see pageouts climbing. In that case beefing your
total memory to 1GB will be like having a new computer.
Finally, I have oversimplified the narrative quite a lot. If you want
to find out more, ask again. There are a lot of people here who have a
plenty of experience in making sure that Word runs as swiftly as it
should.
