Luminous Landscape Forum
Raw & Post Processing, Printing => Digital Image Processing => Topic started by: spphoto on November 27, 2006, 04:11:20 pm
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How big should a scratch disk be?
thanx!
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I believe a good answer is, it depends.
How big are your files you are working on, how much ram does CS2 control on your system, are you working 32, 16 or 8 bit, how many layers etc.
My understanding of scratch disks is that they are similar to windows virtual memory, in that they are a temp, space where CS2 will cache parts of your work while a particular file is open. It's a common recommendation that the drives be independent of where your CS2 software is located on a windows machine most commonly your C Drive.
I work large files, stitches in 16 bit. I have 3 scratch disks allowed to CS2, 2 are independent 36GB scsi drives and the 3rd scratch drive is assigned to another scsi drive on which I also store files. It is the last assigned scratch drive.
While CS2 is working on a file, you can go and look at the scratch disk to see how much of it CS2 is currently using as there will be a temp file created while a particular image is open. You have to look while the file is open since once you close it that scratch file will also be closed. (At least that's the way it's supposed to work, as sometimes I will find temp files sitting on the scatch disk after I close CS2)
Paul c.
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You can also simply look at the size display in PS while you are working to see the current scratch size. On my very largest projects, I used a 20GB file, but YMMV of course.
If you are using SCSI I would say 40GB is a safe size as a min for most work. Using multiple drive allocations for the scratch discs are only needed when using such small drives and you need more swap space (only really big projects).
I happen to use fast SATA2 drives with speeds up there with most SCSI, so I can use much larger drives (SCSI drives are not available in the size range of other formats). I happen use 500GB drives in various configurations. I'm building a new system right now which has a RAID0 array for boot, apps and the scratch file.
Correcting the above post, no you don't separate the PS scratch and windows. You separate the PS scratch file and the windows swap file - which is by default the same as the windows install drive.
In the case of my new system I moved the windows swap to a 3rd standalone 500GB drive which i also use for backup and DVD files.
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lets say a 12 mp camera. I would duplicate the background layer for a safe backup , and use several layers...always working in 16 bit. Scratch disk would be on a second internal drive, probably 350 mb. I could partition it. Question is, how large should the scratch disk partiton be?
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That's far less than what I do with 8MP files typically. Set 50MB and forget about it if you want to partition. Bear in mind the swap separation is physical, not just via partition, so make sure your windows swap is not also on that 350 drive. If you are only partitioning for the sake of another drive letter, ok, but it doesn't do anything. If you are partitioning for swap performance, it won't do anythign either. Realistically just use the drive as-is.
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That's far less than what I do with 8MP files typically. Set 50MB and forget about it if you want to partition. Bear in mind the swap separation is physical, not just via partition, so make sure your windows swap is not also on that 350 drive. If you are only partitioning for the sake of another drive letter, ok, but it doesn't do anything. If you are partitioning for swap performance, it won't do anythign either. Realistically just use the drive as-is.
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kaelaria, I would use a sperate internal drive.
you said, " Set 50MB and forget about it if you want to partition." I'm not exactly sure what you mean here. Do you mean to partition the (2nd) drive for a 50 gb scratch and leave to other 300 gb partiton for backup. Ideally, that is what i want to do....
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Yes that's what I mean, but as I said it won't do anything for performance. What is your reason for wanting a partition just for the swap?
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Yes that's what I mean, but as I said it won't do anything for performance. What is your reason for wanting a partition just for the swap?
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i'm not an expert here.... not quite sure what you mean by swap. It's just that if i buy another drive as a scratch disk to improve ps performance, i'd like to use it as a backup also. Are you saying not to partition the second drive at all, and just use it for both backup and scratch? Is that better than partitioning it? Would this mean i would have to defragment more often?
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Swap/scratch same thing. Yes I'm saying just leave it as one drive unless you had some special reason for wanting the separate drive letter. PS will choose a clear area for the scratch, and unless you are constantly filling the drive, moving the files and deleting them, no you won't need to defrag any more than usual. My backup drives don't even need defrag.
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"Correcting the above post, no you don't separate the PS scratch and windows. You separate the PS scratch file and the windows swap file - which is by default the same as the windows install drive."
You aren't really correcting the post, but simply rewording it.
Each drive in windows has it's own swap file. By default windows is always installed on a the C Drive. Swap is the same as virtual memory, I didn't want to get detailed. I believe I stated you don't want CS2's scratch on the same drive as windows virtual memory namely the C Drive. And yes you are separting the CS2 Scratch and windows which is on the C drive. I don't know a way to pull the paging file for drive C which is the paging file for the OS, off of C and move it to another drive and still have windows OS see it. If you do it's way beyond this discussion.
Not sure why the point of "correcting" my post was necessary.
Paul C.
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You aren't really correcting the post, but simply rewording it.
No, I'm correcting an incorrect statement, as I'll also do below.
Each drive in windows has it's own swap file.
Wrong. Each drive *can* have it's own windows swap file. I have attached my current allocation below. As you will see, I use a single swap file on one drive, which happens to be the default of C: in this case (just a workstation).
By default windows is always installed on a the C Drive.
Wrong. *Most* of the time, people *choose* to install to the C: drive, if they even have the choice available. Many people partition their drive during windows install, or use multiple drives, and install windows to a drive other than C:. Drive letters are set by the BIOS and the physical drive arraingment, not software.
I believe I stated you don't want CS2's scratch on the same drive as windows virtual memory namely the C Drive.
You believe incorrectly, read your original post:
It's a common recommendation that the drives be independent of where your CS2 software is located on a windows machine most commonly your C Drive.
The only separation is between the swap files. It has nothing to do with where windows is installed or where PS is installed.
And yes you are separting the CS2 Scratch and windows which is on the C drive. I don't know a way to pull the paging file for drive C which is the paging file for the OS, off of C and move it to another drive and still have windows OS see it. If you do it's way beyond this discussion.
Obviously you are a windows newbie, I don't even need to point out how wrong that statement is, but it does explain why you are wrong on every single one of your other points. See my screenshot below for where to change your swap file. Control Panel, System, Advanced, Settings, Advanced.
Not sure why the point of "correcting" my post was necessary.
Because everything you said was wrong, how's that for a good reason?
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Well I will stand corrected by an expert, your picture says it all.
Many thanks
Paul C
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You're very welcome
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"And yes you are separting the CS2 Scratch and windows which is on the C drive. I don't know a way to pull the paging file for drive C which is the paging file for the OS, off of C and move it to another drive and still have windows OS see it. If you do it's way beyond this discussion. "
Sorry, no newbee, just not an expert like yourself. I understand where the paging files are controlled by the OS. My point was that if you have your CS2 installed on C where the OS is installed, you don't want the CS2 scratch on that same disk since you can't move the OS's scatch disk from C only change the size of it in the control panel where you pointed it out.
Again thanks for the corrections.
Paul C
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Sorry, no newbee, just not an expert like yourself. I understand where the paging files are controlled by the OS. My point was that if you have your CS2 installed on C where the OS is installed, you don't want the CS2 scratch on that same disk since you can't move the OS's scatch disk from C only change the size of it in the control panel where you pointed it out.
Paul C
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Do you have to be wrong about everything you say? Yes, you ARE a newbie. Don't worry, typical 'users' are newbies, it's not a derogatory term.
Attached below, to again correct your incorrect statements, it's shown that YES you can move the windows swap file ANYWHERE you want or not use any if you so prefer. It is 100% up to you how it's set up. Again, it has NOTHING to do with C:, where windows is installed or where PS is installed, you are completely wrong yet again.
Next?
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Actually I see your point, and stand corrected and see the logic in your statement.
The Windows swap could be set to another drive.
Thanks
Paul c
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..... how large should the scratch disk partiton be?
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It is advised not to use a partition of another drive for your selected scratch disc. Needs to be either your boot drive, or another drive. Now, if you also keep your working files on that other drive, that is fine, so long as it is unpartitioned.
Consider a 10,000rpm drive (under 100GB) if you have adequate ventilation.
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The main thing to remember is that moving to a different drive letter on the same physical drive does nothing for performance; you must move to a different physical drive so that the PS swap file and Windows page file are on separate physical disks.
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On the subject of drives, yes a 10,000 RPM drive (of any format) is an excellent performer. I do use Raptors at the moment but will not be using them again in my next system (should be online tonight woohoo) due to the increased noise.
They are also only a few percent better than the newest SATA2 drives in overall performance. Seek time is exceptionally better, nearly 1/2, but in real use seek time is not the single most important factor to performance.
Now that SATA2 performance is so close, and they are available in capacities 7x greater than 10,000 drives, and they are cheaper, and they are silent, and they run much cooler - I only recommend 7,200RPM SATA2 drives now. I would not have said the same thing a few months ago though!
If you have a conventional air cooled (fans) system though, you won't hear them, so go for it if you want top-notch performance for a great swap disk!
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On the subject of drives, yes a 10,000 RPM drive (of any format) is an excellent performer. I do use Raptors at the moment but will not be using them again in my next system (should be online tonight woohoo) due to the increased noise.
They are also only a few percent better than the newest SATA2 drives in overall performance. Seek time is exceptionally better, nearly 1/2, but in real use seek time is not the single most important factor to performance.
Now that SATA2 performance is so close, and they are available in capacities 7x greater than 10,000 drives, and they are cheaper, and they are silent, and they run much cooler - I only recommend 7,200RPM SATA2 drives now. I would not have said the same thing a few months ago though!
If you have a conventional air cooled (fans) system though, you won't hear them, so go for it if you want top-notch performance for a great swap disk!
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Great discussion. I plan on getting a second HD for scratch and storage, what would you recommend in regards to size and brand, how big should I go? This would be going into a Dell 380 precision work station.
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In actual use, the difference between most brands given the same type of drive, is barely, if at all noticeable.
What you can use is determined by your controller (motherboard in most cases). The major interfaces are IDE (older systems than 2 years), SATA (1 year old systems, also called SATA150), SATA2 (current systems, also called SATA300) and SCSI (requires a dedicated controler card, not standard equipment).
The latest version of SCSI (there are over a dozen) is the fastest by a bit, but the cost is many times that of the other types. Not recommended.
SATA2 as an interface has excellent performance. There are many drives on the market for it right now, and they have several features you need to look for to maximize it's performance. NCQ (Native Command Queing), a 16MB buffer (as opposed to 8 or 2) and a high rotation speed are the three big factors. Most drives have a rotation speed of 7,200rpm while the Raptor models from Western Digital are at 10,000. The Raptors are a little special, I'll touch on them below. Basically pick a SATA2 drive with NCQ and a 16MB buffer at whatever size you want - shop for a good deal or sale, they are all very similar in performance. WD, Seagate and Maxtor are the big names.
SATA is still very popular even though it was only mainstream for 2 years. It was the replacement for the older, slower IDE interface but SATA2 came along very quickly. Manufacturers however still support it with new models all the time. As with SATA2 pick a large buffer and the size of your choice. NCQ as far as I know is not available with SATA.
IDE drives used the old flat ribbon cable like optical drives now do. It's very slow in comparison and unless you don't have a choice, don't consider an IDE hard drive. Buffers went to 8MB on them.
The Raptor line was designed to replace SCSI drives on workstations as a cheaper alternative. They quickly found a home however in high end game systems due to the increased speed over any other drive at the time. Raptors only come in 3 relatively small sizes and are all only SATA. This however is not a problem, as they are still faster than any SATA2 drive, albeit not by much anymore. They only use 2 platters and use parallel head access for exceptional seek time (they find data to read much faster, less waiting). Because they spin 2,800 faster than the others, they can also move that data at a faster rate, at least when multiple files are being addressed.
Where they fall short now, is in raw throughput. A SATA2 RAID0 array can put out almost double the data in raw throughput. You want that where you are serving large files, or concurrent files - like a database or large file server. I honestly don't know how a PS swap file would be catagorized, I never tested it. I don't know if it would be accesed as a large file or lots of small files. Raptors also have a couple other drawbacks due to the 10,000 RPM speed. You can hear them, like a quiet CD burner spinning all the time - and they give off a lot of heat and need active cooling - either water or a dedicated fan on them (most cases have a fan near the hard drives).