> From: [EMAIL PROTECTED] > Subject: Re: [PCI] Virtual memory > > At 10:33 AM +1000 06/23/2004, David Elmo wrote: >> OK Dan, I am sure you have *something* here. But I don't know about your >> "100%" correct" remark. My PS 5 shows no trouble with VM on, perhaps because >> I have 500 MB of real? > > Probably. 500 MB RAM is a Good Start. If you only manipulate small > files, you'll probably never feel any of the problems. > > Try some complex manipulations of something that's even 1/4 low-end > publishing quality, 800 dpi, 50 to 100 MB TIFF file or larger. Add > layers, run effects, etc. > >> I still would like a pointer to references by PS that >> clearly acknowledge trouble with VM on when there is plenty of RAM. I had a >> quick look at Adobe and did not see what I would have expected to see if it >> was "100% correct". Nor in my help files on PS 5. > > Well, you'll just have to do more than a "quick look". The > information is there and has been beaten to death in the forums and > usenet for years. Frankly, tho, why bother? If you don't feel the > thrash currently, it's moot to you. If you do eventually feel it, > then you now know what it is now... > >> One obvious trouble with >> VM where real is scarce is the slowness of system and PS program resources >> having to be read back and forth from HDs. But this is not "thrashing" >> about. It is just slowness. > > If you feel that then you're on the very edge of the problem. > > A single write-then-read cycle, that lasts a few seconds, is a page > swap. Any more than that, you're Thrashing. Your HD is capable of > transferring many megabytes per second. hum. I started to say "No > application really needs more than a few dozen megabytes to run in > the near term (next thousand quanta) - that's maybe 1 to 5 seconds of > disk i/o max! More than 5 seconds? You're thrashing." But > obviously there are cases, expecially Photoshop, where that's not > completely true. And the faster your processor the faster the app > can finish with the alloted memory. Well, everything is Relative. > You know what I mean. :) > > In most cases, thrashing has an end to it. Oops you use too much > memory. The applications fight each other for time and RAM. You > thrash a bit, then it settles down. In Photoshop, the thrashing > builds. It gets worse and worse, longer and longer, as you use it. > Eventually, you spend more time twiddling your thumbs listening to > the HD than you do working... > > - Dan.
Well, Dan, I think we are getting nowhere on this. I was wanting Adobe admissions because I have no evidence of conflict of PS with VM. And slowness is a feature of HD activity, it is a fact of life, it is not particulary relevant to this discussion in that even PS uses "scratch disk" HD space separate from VM and it too is slow and on your generous understanding of "thrashing", thrashes with VM off. I do deal with big files, yes, over 100MB and often do such impressive things to them that my knees go weak and tears flow at the sheer beauty and skill. But I don't get freezes in this activity. I associate big trouble with freezes. Slowness is something to maybe get a bit mad about but really something to bear as a limitation. A freeze is something to get more than a little mad at, something to make a placid fellow behave like a wild wrecking rock star at the end of a concert... :) David Elmo -- PCI-PowerMacs is sponsored by <http://lowendmac.com/> and... Small Dog Electronics http://www.smalldog.com | Refurbished Drives | -- Sonnet & PowerLogix Upgrades - start at $169 | & CDRWs on Sale! | Support Low End Mac <http://lowendmac.com/lists/support.html> PCI-PowerMacs list info: <http://lowendmac.com/lists/pci-powermacs.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/pci-powermacs%40mail.maclaunch.com/> Using a Mac? Free email & more at Applelinks! http://www.applelinks.com
