on 5/27/03 4:10 PM, Bill Hatchell at [EMAIL PROTECTED] wrote: > on 5/27/03 1:18 PM, Illovox Media at [EMAIL PROTECTED] wrote: > >> 9.1 w/o vm turned on is fast and best. 9.0 is a dog. many bugs. > Why turn VM off? There seems to be some controversy re benefits of VM. >
With VM off, the OS loads all the app's executable code at once, which makes application launch take longer. This is done to ensure that there is enough room remaining in RAM to support running the app. With VM (or RAM Doubler) on, the OS only loads those portions of the executable code that are immediately needed to support getting the app to its initial running state. This shortens the initial launch time because the OS will page in additional code as needed. If you've got an app with LOTS of menu commands all having their own swatches of code, this should result in a much slimmer RAM profile and a much faster load time. One 'gotcha' is that the paging in of not-yet-loaded code can slow the app down by varying degrees *as you're using it*. The other 'gotcha', in the mobile computing context, is that VM paging causes the HD to spin up. My experience... On battery, VM = off (although you could use RAM Doubler set to the 1.0x setting that enables the faster app loading and costs completely negligible amount of time). On AC power, VM = RAM size + 1 MB. This gives the faster app loading and you essentially never will page an entire app out to disk (i.e., when your RAM would be filling up anyway, you still run out of VM, although theoretically you could launch just one more really tiny app...). I have never encountered a case where I could notice any delay due to the OS paging in not-yet-loaded code. - Eric. -- Eric Strobel ([EMAIL PROTECTED]) ===================================================================== Bioweapons? HA! I laugh at them!! *I've* cleaned the coffee urns at work!!!! ===================================================================== -- PowerBooks is sponsored by <http://lowendmac.com/> and... Small Dog Electronics http://www.smalldog.com | Enter To Win A | -- Canon PowerShot Digital Cameras start at $299 | Free iBook! | Support Low End Mac <http://lowendmac.com/lists/support.html> PowerBooks list info: <http://lowendmac.com/lists/powerbooks.shtml> --> AOL users, remove "mailto:"; Send list messages to: <mailto:[EMAIL PROTECTED]> To unsubscribe, email: <mailto:[EMAIL PROTECTED]> For digest mode, email: <mailto:[EMAIL PROTECTED]> Subscription questions: <mailto:[EMAIL PROTECTED]> Archive: <http://www.mail-archive.com/powerbooks%40mail.maclaunch.com/> Using a Mac? Free email & more at Applelinks! http://www.applelinks.com
