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Boots
01-14-2005, 02:43 PM
In Ill CS, I have not been able to pin down the actual temp file and observe it or measure it. I can observe the disk activity for the designated scratch disk, but it doesn't appear to write a temp file when opened. Only when Saving have I seen disk activity on the designated scraatch disk. But no visible or invisible file is left behind like Photoshop does.

Did a little more investigating and this is weird and strange and interesting.

Ill CS/OSX makes two temp files when first opened. Both files disappear immediately when Illustrator is quit.

Both files are located at /.private/tmp/501/temporaryItems.
The first is "Acr224620.tmp" with a preview 'pdf' icon. It crashes Preview when attempted to open, but does open and shows code in TextEdit. It stays at 4kb for the duration and does not appear to be modified by changes in the open Ill CS doc.

The second file- "Acr235700.tmp" however does change when changes are made to an open Illustrator CS doc:

With a large Ill CS doc open which shows as 35MB in the Finder, the above mentioned "Acr235700.tmp" shows as 16.5MB in the Finder.
Ill CS's designated scratch disk is a 4-drive SCSI stripe but there is no evidence of a temp file on it. But when I make a change to the open Ill CS doc, and then Save- there is massive I/O activity on the designated scratch disk (but no visible or invisible temp file). Then I check the "Acr235700.tmp" at /.private/tmp/501/temporaryItems and it is modified at the time of the Save, and now shows as 31.8MB....

Apparently with Illustrator, it'll take as much memory as is available. (I would assume up to the neighborhood of 2GB)

From Illustrator Help:
"Depending on how much memory is available, you can undo an unlimited number of the last operations you performed, in reverse order, byśrepeatedly choosing the Undo command."

Making another minor change to the same open Ill CS doc, and then a Save-
There is again massive I/O activity on the designated scratch disk (but no visible or invisible temp file). Then I check the "Acr235700.tmp" at /.private/tmp/501/temporaryItems and it is again modified at the time of the Save, and now shows as 47.1MB....

So it appears Illustror CS is using the startup disk in a big way to cache for undos at least, and even with a completely different "Primary" scratch disk- and then the designated scratch disk to help write the changes to disk.

More testing to pin down just how it uses the designated ('Primary') scratch disk- I'll have to use a slower volume!

Very interesting.

Chris Billington
01-14-2005, 07:02 PM
Amazing stuff. And obviously as you say, very interesting. Maybe you remember I have been pretty much rebuilding my old Sawtooth so I could launch off into some species of digital graphics. I certainly couldn't afford the full Photoshop, but Photoshop Elements was well within my means. I have been exploring the program for a couple of weeks now. If I have understood correctly, it offers a setting choice for how much ram it uses, default to 50%, (which means 625MB in my case), but this concept of a scratch file has been something of a mystery. I'll be lurking this section of the forum pretty regularly so I can get a better grasp of what's going on.
Elements may well be Photoshop Lite, but it seems to be capable of a lot of modification of images from the most delicate touchups to outright mashing (He wrote gleefully).

Onward. Onward. CB :dance: :dance: :dance:

Boots
01-15-2005, 06:44 AM
Hi Chris, how are you? :)

I have PS LE, Elements 1 & 2- I don't have Elements 3 yet.
They all do most of what the full versions do and are quite worth the money.

I think you could up your 'max used by Photoshop' to 70%, and you should see a nice improvement.
I forgot your exact config, but I see you've two internal drives, no? And you could make part of the non-system drive the 'designated scratch disk' for Elements which will improve its performance again.
How are your drives presently setup?

Basically, the scratch file is a normally-invisible temp file that gets created on the DSD when you open Pshop. It grows and shrinks in size depending on the image size and how many 'history states' are recorded. ..But I've forgotten now, does Elements allow History states or just multiple Undos? I don't have it on my rig at the moment to check.
Anyway, every time you do something to change the image, the change gets written to the scratch disk and/or the scratch disk gets used to update the image file with the change- especially if not enough RAM available to contain the image file in entirety. The designated scratch disk always gets used no matter what.
So it's just about always a boost to let the non-system drive do it.

Chris Billington
01-15-2005, 01:25 PM
Hi Chris, how are you? :)

I have PS LE, Elements 1 & 2- I don't have Elements 3 yet.
They all do most of what the full versions do and are quite worth the money.

I think you could up your 'max used by Photoshop' to 70%, and you should see a nice improvement.
I forgot your exact config, but I see you've two internal drives, no? And you could make part of the non-system drive the 'designated scratch disk' for Elements which will improve its performance again.
How are your drives presently setup?

.

Boot-up drive is the SATA160. Available 147.19GB. Everything is on this drive. I am backing-up to the ATA120. Available103.19GB. No partitioning at present.
To quote from the Elements Help viewer....
'For example, if you select, paint, and rotate part of an image, each of those states is listed separatetly in the Pallette. You can then select any of the states and the image reverts to how it looked when that change was first applied. You can then work from that state.'
And then further..
'By default, the Undo History pallette lists 50 previous states. Older states are automatically deleted to free more memory for Photoshop Elements. You can change the number of states displayed in the Undo History pallette in General Preferences. The Maximum number of states is 1000.'
So that seems to indicate more than just multiple Undos. But then, how could there be multiple undos without there being multiple History states?

In the General Prefences pane, there is a window which allows selecting which drive gets to do the scratch file. I could select the ATA120. Is that all I would need to do if that would be a good idea? As in, No partitioning necessary? This is a quote fron the Photoshop Acceleration Benchmarks (Discussion) answer given to jjlphoto
'If using the drive containing startup system as scratch, don't partition it for a second volume for scratch. Performance will be faster as one volume for system/apps/users-data/PS scratch. Particularly since you'll have plenty of free space on the volume.'
I assume scratch files are not retained on the system unless I choose to archive them?

OK. Enough for now!! Coffee calls.
:cool:

Chris Billington
01-15-2005, 08:08 PM
So that seems to indicate more than just multiple Undos. But then, how could there be multiple undos without there being multiple History states?
This just begs for the question to clarify what, if anything, is the difference/relationship between an Undo and a History state.

In the General Prefences pane, there is a window which allows selecting which drive gets to do the scratch file. I could select the ATA120. Is that all I would need to do if that would be a good idea? As in, No partitioning necessary? This is a quote fron the Photoshop Acceleration Benchmarks (Discussion) answer given to jjlphoto
'If using the drive containing startup system as scratch, don't partition it for a second volume for scratch. Performance will be faster as one volume for system/apps/users-data/PS scratch. Particularly since you'll have plenty of free space on the volume.'

I gotta take a shot at clarifying what I was going for here.
If I were to partition the ATA120, say 50/50, and title them Vol A and Vol B, Vol A would be the faster to access, and should be the designated scratch file. Vol B I can use as back-up. Then I should use the Elements General Preferences to designate which Vol on ATA120 is to be used for the scratch file. Is that all? No command line work to point to the appropriate Vol? I think that's clearer.
Thanks Boots. CB
:o

Boots
01-16-2005, 06:18 AM
Mornin' Chris- sorry, I was too wiped out last night to get to an answer.

Sounds like indeed PE has History States just like full version, which are of course stored in the temporary file aka 'scratch disk'. And the same allowable as full version of Photoshop- 1000.

And yes, very simple and easy. First partition will be the fastest and then in PE prefs designate that first volume (first partition) of second drive as the 'scratch disk'.

What size files do you work on?. The more History states and the bigger the image file the bigger the 'scratch disk' file. I did a little experiment on a- I think it was, a 30MB file or so- with 500 History States. Temp file grew to I think 30GB when all was said and done....History States are fantastic because you can paint from them on to the current image. Absolutely fantastic.
But that's why you need a big honkin' scratch disk volume. And the faster it is the better. Helps Pshop speed all around.

Chris Billington
01-16-2005, 10:38 AM
I have upped the 'Max used by Photoshop' RAM to the suggested 70%. I partitioned the 120 ATA; 70GB Vol_A, 50GB Vol_B and designated Vol_A to Scratch. I fancy, as you predicted, the program is snappier. Success. There wuz good tweaking this morning!!!

CB :dance: :dance: :dance:

Chris Billington
01-26-2005, 08:27 AM
Mornin' Boots.
I copied this from the closed thread you put up yesterday I think.
Given this quote here:-

'Keep your Photoshop files as small as possible so most or more of the work can be done using the installed RAM, rather than the internal hard drive.'

Indeed I see how large these Photoshop files get and how very quickly too especially while I am blundering around in the App. trying for a little intuitive control!!!! I can't help wondering if you are implying that there is a strategy for keeping the files small? I see your advice was aimed at a user with an iMac or some such machine, and since I have the G4 tower and two internal drives, my circumstances are quite different. But I'm curious anyway.

CB :dance:

Boots
01-26-2005, 09:47 AM
Hi Chris,
The general advice for keeping Photoshop "working" files as small as possible applies to all users across the board as a powerful 'tool' to maximize speed and efficiency.
Unnecessary delays are the result when creating or working on image files which are larger than needed for specific output requirements.

Here are some of Adobe's particular recommendations on the subject:

"Minimizing Resolutions
You can minimize the size of your files by reducing their resolution, which is measured in pixels per inch (PPI). Photoshop requires more memory and disk space to process high-resolution images, which increases the time it takes to display, process, and print them. Increasing the resolution of an image does not always improve the quality of the image, but may instead only increase its file size. You want the resolution of images to be the highest value your printer can use. Resolutions higher than that only add information that your printer can't use, but must process, thereby increasing print times.

For continuous-tone images, such as photographs, that you plan to print, begin by using a resolution that is 1.5 to 2 times the screen frequency, measured in lines per inch (lpi), that you'll use to print the image. For line-art images, such as drawings, use the same value as your printer's resolution, measured in dots per inch (dpi). For example, if the resolution of your printer is 600 dpi, and you plan to print the image using the printer's default screen frequency of 85 lpi, save continuous-tone images at a resolution between 127 ppi (85 lpi x 1.5) and 170 ppi (85 lpi x 2), and save line-art images at a resolution of 600 ppi.

Recommended resolutions for continuous-tone images:

Macintosh monitor: 72 ppi
Windows-compatible monitor: 96 ppi
300 dpi laser printer: 100 ppi
600 dpi laser printer: 150 ppi
725 dpi inkjet printer: 150 ppi
1200 dpi or higher imagesetter: 1.5 x the screen frequency (lpi) value you specified"

Chris Billington
01-26-2005, 10:16 AM
One further question then......
If a file is at a particular resolution (based on what a particular printer can work with and to some extent the capacity of a monitor), can the resolution of a finished image be increased at some later time? I have the thought that I would like to see a processed image quite large (as a print), say 48x48. I realise that the appearence of such an image would also depend on the printer it would be run on. But once saved at a particular resolution, can that resolution be changed?

CB :eek:

Boots
01-26-2005, 12:30 PM
Yes, you can change the resolution of an image at any time by enlarging or decreasing the size of it by resampling.
However, when you do so you are not adding detail or information- you are only adding more pixels or subtracting pixels. This alters the content of the image.

Depending on how it is done, the results may or may not be as good as the original. There are various third-party Photoshop plug-ins and stand-alone software which specialize in this kind of operation. There are also particular techniques developed by Photoshop experts which can maximize the quality of such a tranformation.

When you scale an image to make it appear on-screen or print larger or smaller, you are maintaining the same number of pixels but each pixel is either larger or smaller. The actual content of the image remains the same.