On Thursday, January 1, 2004, at 10:37 PM, Colin Shapiro wrote:
> I'm not fully up to speed with this but....
> Folks on the VSL forum have been talking about Panther and a
> so-called "Swap-file" which is used by the system. Apparently folks
> like us who use audio and EXS24 with lots of samples need to keep
> this swap-file on a separate drive - maybe someone else could jump in
> here with more detail.
>
Memory management, VM, swapfiles and 'pageouts' are something you
should learn all you can about, as lack of attention to memory
management is probably the biggest single factor in systems not
performing up-to-par.
Especially if you are on an older machine!
There is avery good article which explains VM, in broad terms, here :
http://arstechnica.com/reviews/01q4/macosx-10.1/macosx-10.1-6.html
[even though slightly outdated].
Fundamentally, you need about 4 or 5 gigs of free drive space on your
startup drive to allow for VM under Panther. a little less under Jaguar.
If you don't have this, you should move your swapfile to another
drive, as you run the risk of it eating up your prefs [take it from me
, rebuilding Mail prefs is no fun :( ]
That figure does not take EXS's VSM into account. [I can understand why
this issue showed up with VSL users first :) ]
VSM combined with VM is probably going to generate a lot of disk I/O
activity, even if you do have plenty of RAM and plenty of free space,
so i can understand why VSM users are recommending moving the swapfile.
[preferably to a drive dedicated to that alone, if you are serious user]
Read more here:
http://www.macosxhints.com/article.php?story=20020410233454624
Most importantly, remember that if you use more than one memory-hungry
app at a time [especially two or more Audio apps] the swapfile will
grow very quickly, resulting in excessive pageouts and a serious
decline in performance. The only cure for this situation is to restart
the computer to clear the swapfile. [if it happens a lot, you need more
RAM]
In jaguar, you can run a utility called memorystick which will keep you
abreast of the VM situation. In panther you can choose to have Activity
monitor display a pie-chart of memory usage in the dock.
By monitoring VM, you can choose to restart the computer at your
convenience, rather than having everything fall in a heap first.
Dave Eager