17 Replies Latest reply on Jan 14, 2013 10:00 AM by TLL...

    Partition Large Scratch Disk ?

    parisphoto Level 1

      Running PS CS6, Vista 64, 32MB memory.

      My scratch disk is a fast internal drive of 275 GB.

      This drive is only used as a scratch disk and the tempory storage of files.

      I realize that I can view the Efficiency %, but would it be beneficial to partition this drive, giving PS it's own partition?


        • 1. Re: Partition Large Scratch Disk ?
          Curt Y Level 7

          Most consider partitioning a poor option.  For the "neat freak" it does have some allure to have it on a seperate disk volume.

          • 2. Re: Partition Large Scratch Disk ?
            TLL... Level 3

            "32MB memory" really? If it's 32GB I'm envious


            I agree with not partitioning. I've also set the PS scratch drive space on my workstations for Bridge cache files. It improves both I believe  to have a separate disk space from data and apps.

            • 3. Re: Partition Large Scratch Disk ?
              Noel Carboni Level 8

              I agree with Curt and TLL - partitioning a spinning HDD almost guarantees you extra seeking (and thus big slowdowns) if anything in another partition is accessed around the same time as Photoshop scratch.  Plus, you divide up your free space, and Photoshop has been seen on occasion to use more than 200GB of scratch space (e.g., if you're stitching mosaics).


              If you ARE seeing thrashing because of multiple things accessing the drive, or just want to speed Photoshop's swapping up even more, something you might consider is replacing it with (or just adding) an SSD drive.  Last month I was able to pick up an OCZ Vertex 4 256GB drive for only $159.


              Hey TLL, I put 48GB in my Precision T5500 workstation. 



              • 4. Re: Partition Large Scratch Disk ?
                Hudechrome Level 2

                I disagree. It's fine not to partition a disk that is totally used for scratch, but if you also store files, then the fragmentation problem shows up.


                I have a 40G partition for my main Scratch (yes, only 40G. Even big stitches do not max out the drive) and suffer no consequences I can see for doing so.

                • 5. Re: Partition Large Scratch Disk ?
                  TLL... Level 3

                  If got a 300gb 10k WD for scratch and often chew up 200 of that on mosaics. Just one more year left on my 'corporate' T5500 (maxed out @24gb, so I'm told) - then on something new with nothing less than 96GB!  @home, not so much...

                  • 6. Re: Partition Large Scratch Disk ?
                    Noel Carboni Level 8

                    The T5500 can take 8GB DIMMs, up to 6 of them in single processor config and 9 of them in dual processor config.


                    So that's 48GB max in single processor config or 72GB max in dual processor config.




                    It's possible they might have to replace DIMMs you already have (and are unwilling to do so because of the cost), assuming you don't have 8GB DIMMs.



                    • 7. Re: Partition Large Scratch Disk ?
                      Noel Carboni Level 8

                      What fragmentation problem, Lawrence?


                      Windows has been defragging itself on a schedule since Vista.



                      • 8. Re: Partition Large Scratch Disk ?
                        Hudechrome Level 2

                        What partition problem Noel? It needs no defrag at all.

                        • 9. Re: Partition Large Scratch Disk ?
                          Noel Carboni Level 8

                          The partition problem is that it ALWAYS forces seeking.  It's like worst case fragmentation, because you're forcing the files to be on different physical parts of the disk, far apart.


                          Anyway, the problem is moot.  The really right answer is to use SSD from here forward, which have no seek time and only the tiniest bit of extra overhead added byr fragmentation.



                          • 10. Re: Partition Large Scratch Disk ?
                            Hudechrome Level 2

                            That first scenario is a red herring. First of all, if true, it means you are writing both scratch and files simultaneously. I can envision maybe two conditions that would be true; one is if you have paging on that disk and/or two if you are so ram deficient as to be constantly swapping during a Photoshop session. In any case, either setup is problematic. But what I have on the second partition are files never encountered by Photoshop; legacy downloads, personal stuff, music etc. It is also my dual boot drive.


                            Another reason to partition is to put scratch at the beginning of the disk for greatest data transfer speed. Consistently. I found this to be the most noticeable outcome once I employed this technique.


                            Of course, SSD's do solve that problem. They do have their own, one of which is cost. A 250G HD is peanuts compared to the same size SSD.


                            You must remember to disable auto defrag for the SSD.

                            • 11. Re: Partition Large Scratch Disk ?
                              Noel Carboni Level 8

                              It's a good and important point to differentiate "multiple" use of the scratch drive from "simultaneous multiple" use.  If you're doing Photoshop, which is usually a fairly immersive experience, chances are you're not doing a lot of other work simultaneously - but it's not an impossibility.


                              In my own experience, I multitask a lot - probably more than most - as my business requires a lot of different things of me, the reality has been that using a secondary disk drive for scratch (back when I used a spinning HDD for Photoshop scratch) and other things did not result in unreasonable fragmentation and performance loss.  What was MORE important was having plenty of free space on the occasions where Photoshop needed bunches of it.  If I had cordoned off just a hundred GB or so in a partition, I would have found it too little.  Of course, not everyone works on equally large projects.  But it's a given that almost everyone fills their disks to near capacity.  Pooling the free space can be a real practical issue.


                              Yes, an SSD is more expensive than an HDD today.  But not more expensive than an HDD of yesteryear.  The most recent SSD I purchased (on sale at Amazon) cost $159 for 256GB, which is 62 cents per gigabyte, and it was a fairly high-end unit (OCZ Vertex 4).  $159 is less than the cost of a Photoshop perpetual license upgrade.


                              Now that the concerns for "over usage" have pretty much evaporated (modern SSDs all have "wear leveling"), it's pretty hard to imagine an incremental investment other than an SSD in a computer that will return a better performance payback.



                              • 12. Re: Partition Large Scratch Disk ?
                                Curt Y Level 7



                                In regards to SSD vs spinning HD.  The average HD has a limited lifespan before failure.  The high end drives have a longer expected life.  With the current crop of SSD how does its life span compare to the high end drive?


                                Also, is a SSD a plug and play (windows OS) or does one need to install and configure a controller?

                                • 13. Re: Partition Large Scratch Disk ?
                                  Hudechrome Level 2

                                  One's cash flow has to be considered, even today.


                                  Anyway, here's my "discount Factor", that is, how I work and why I obtain the results I do.


                                  My principle source of images is my D90, a 12.2MP file size. I have run stitching up to 6 frames. I have 12G Ram on a 64 bit system. I have about 40G Scratch.


                                  I never have run out.


                                  I recently did a 6 panel stitch from a loaned D800.


                                  I still didn't run out.


                                  Photoshop is set at 75% Ram usage.


                                  That D800 stitch would definitely have been much faster had I used an SSD, especially since the scratch is only a 5400RPM drive. But as I have said, scratch is now seldom an issue so it really is a non issue until I buy that D800 and my computer gets an overhaul.


                                  Computers share with other systems the same considerations. Where in the chain from acquisition to output will you get the best bang for the buck in upgrades?

                                  • 14. Re: Partition Large Scratch Disk ?
                                    Noel Carboni Level 8

                                    With apologies in advance I'll delve into a bit of geekiness...


                                    Current wear-leveling SSDs have lifespans measured in years if you write tens or even hundreds of GB to them per day.  The larger capacity SSDs have longer lifespans, simply because there's more NAND flash to spread the writes over.


                                    Any given NAND flash block has a write/erase lifespan of thousands to tens of thousands of cycles.


                                    Using very simple and conservative math, and assuming you can write every single NAND block only 1000 times, this means you could ultimately write 256 TB to a 256 GB SSD.  If you wrote 100 GB a day (which is quite a lot in practical terms) to that disk, it would take 2560 days to write 256 TB.  2560 days is 7 years!


                                    Increase the size of the SSD, or use an array to spread the load, and the amount you can write goes up proportionately.


                                    With my 2 TB SSD array, for example, using the same math I could write 1 TB a day for 2000 days - 5+ years.


                                    Most modern SSDs emphasize good compatibilty and simply plug into a SATA port.  That said, SATAIII (6 gigabit/second) controllers aren't all that common yet, so to get the maximum performance you might actually want to add a good PCIe SATA controller (and not all are good).  But even with SATAII (3 gigabit/second), SSD transfer speeds are generally 2 to 3 times as fast as with HDDs.


                                    With some Apple systems there may be a special process of formatting required before OSX will "see" the drive.  That's fairly well documented and supported by utilities.


                                    Within the past year SSDs have "arrived", changing from being persnickety things only an enthusiast could love to being a commodity that anyone should be able to use.



                                    • 15. Re: Partition Large Scratch Disk ?
                                      Hudechrome Level 2

                                      Is it sufficient to install the OS and apps by simply using the backup? I expect this is true for HDD's.


                                      If so, then the easiest way to proceed is to do a backup first, then copy it to the new drive.

                                      • 16. Re: Partition Large Scratch Disk ?
                                        Noel Carboni Level 8

                                        Most people suggest doing a fresh OS installation on the SSD, but if you have a well-tuned Windows setup you can save a Windows System Image backup and restore it to an SSD that's capable of holding the entire partition.  If you have a bit less SSD than HDD space, and know the exact sizes in allocation units you can shrink the partition before making the image.  This is exactly what I did when moving from a slightly larger HDD array to a slightly smaller SSD array.  My total downtime with 600GB of data on drive C: was less than 8 hours - basically I started the restoral in the evening and had a working system the next moring..


                                        And it's helpful to know that you can always reinstall the HDD if something doesn't go as planned.


                                        Oh, and Windows may notice you've changed the hard drive and ask you to re-activate it.  If this doesn't just go straight through in automated fashion, you need only call them and explain that you've restored a backup, at which time they will facilitate reactivation.  I've done it twice with the same system, actually - once when I moved my HDDs from a T5400 to T5500 workstation, and once when I upgraded from HDD array to SSD array.



                                        • 17. Re: Partition Large Scratch Disk ?
                                          TLL... Level 3

                                          Thanks, that's good to know. Maybe I can 'donate' my 24gb (6x 4bg) to a coworker and get 48 this year!