7 Replies Latest reply on Aug 11, 2012 12:07 AM by Farrellart

    new system with 32gb Ram.....CS5.5 using alot of scratch disk

    Farrellart Level 3

      Hi All,

       

      Been away from these forums for a while.

       

      OK. I have just built my new rig (Asus p9x79 pro, 32GB 1600Mhz DDR3, Intel 3820, old GTX285 1GB, Win7 pro.....many hard drives ) as I am working on a very big project producing 440x240cm200ppi digital drawings to be installed as lightbox artworks at the same size.

       

      My old system just could not cope with the demands I was putting on it as It only had 12gb RAM. I have two scratch disks set up x1 30gb SSD (dedicated) and x1 240gb SSD ( has other stuff on it with 75gb free ). I am also using Photoshop CS5 Extended (updated) with RAM usage set to 80% (23976).

       

      While I realise PS will still make use of the scratch disk despite the amount of RAM I was shocked to see the first drive (30gb) was almost full with 5gb space left when I loaded the PSB file with x9 layers. Looking at the meta data in Bridge it tells me the file size is 6.90GB with pixel dimensions of 34646x18898@200ppi. Windows reports that I am only using 20GB of my 32GB......

       

      Shouldn't PS be using more RAM before going to the slower reads on a  SSD? Windows Task Manager tells me I have 8150 RAM cached, 12310 RAM Available and 4215 RAM Free.  If Photoshop is not using the 12GB would it be wise to make a 9GB RAMDISK for an addition boost...not even sure if that would work, but, I hate the feeling of having all that RAM and 1/3 not being used.

        • 1. Re: new system with 32gb Ram.....CS5.5 using alot of scratch disk
          Level 5

          You referred to the answer to your puzzlement yourself when you typed "I realise PS will still make use of the scratch disk despite the amount of RAM" [emphasis added].

           

          Photoshop creates the scratch disk the instant you open an image file or create a new one.  It sets its initial size based on its size, number of layers, history states, etc., regardless of installed RAM.  It starts using the scratch disks from the get go, moving stuff off of the scratch disk into RAM and viceversa as Photoshop sees fit.

           

          When setting up a scratch disk, figure on at least 100 times (or more) the size of your largest file, multiplied by the number of files you keep open at any given time.

           

          The total amount of scratch disk space on your two drives (30 GB + 75 GB) is not that large, as per the above calculation.

           

          Just for reference, my dedicated primary scratch disk is a 300 GB physically separate internal hard drive, and I also have other drives set up as secondary, etc., hard drives.  Other users have a lot more scratch disk space than I do.  I normally have no more than two files open in Photoshop at once, occasionally three or four.

           

          Also keep in mind that the percentage of memory you allocate to Photoshop is not a percentage of total installed RAM but of available memory at any given time after the OS and other applications you have running have grabbed the RAM they need.  Therefore the calculation you made is not necessarily accurate.

           

          As to creating a RAM disk, I supposed there's no harm in trying, but the real question is whether you are seeing any real performance problems now, rather than just calculating RAM figures that may or may not be that relevant in actual use.

           

          Conceivably, you could also get a much larger SSD as your primary scratch disk.

          • 2. Re: new system with 32gb Ram.....CS5.5 using alot of scratch disk
            Farrellart Level 3

            Thank you for you reply. Very useful.

             

             

             

            I have been playing around and it's now clear, the amount of layers especially at that size will have a dramatic effect on the Scratch Disk....the P9x79 has SSD caching which I will explore as a solution as it looks like you can get 5GB/sec (youtube Asus) - looking to get 1TB HHD with 240GB SSD cache ......who need money anyway ....I will investigate the RAMDISK idea to see if it makes a difference in the mean time.

             

            Thanks again for your help.

            • 4. Re: new system with 32gb Ram.....CS5.5 using alot of scratch disk
              Noel Carboni Level 8

              Farrellart wrote:

               

              looking to get 1TB HHD with 240GB SSD cache ......who need money anyway

               

              I have read many reports of people who have gotten into trouble using SSD caching, though I don't know about your particular hardware.  The added complexity simply seems to increase the chance of faults and data loss.

               

              A single SSD can only transfer up to something less than 600 megabytes / second through a SATA 3 link, simply because the link is 6 gigabits.  Any benchmark showing higher must be influenced by a RAM cache, and the numbers don't represent true throughput.

               

              But your idea is on the right track.  If you're really looking to speed things up on a powerful system like that, build a RAID array of multiple modern SSDs and use it for drive C:.  I have a 4 x 480 GB SSD array and it screams, with about 1.7 gigabytes / second throughput.  I can hardly notice when Photoshop goes to its swap file.

               

              ATTO 4 Vertex 3 SSD on SATA 3 2720SGL August 2012.jpg

               

              -Noel

              • 5. Re: new system with 32gb Ram.....CS5.5 using alot of scratch disk
                Farrellart Level 3

                Thanks Noel for the Heads Up on the SSD caching issue. I will look in to the details on a RAID configuration , I may need your help with the raid setup - it's new to me

                • 6. Re: new system with 32gb Ram.....CS5.5 using alot of scratch disk
                  Noel Carboni Level 8

                  Just so you know:

                   

                  I can say with conviction that my RAID 0 array of SSDs works great, but I'm not sure I'm fully qualified to help build a system different than the one I chose.  Some folks do find controller incompatibilities and whatnot, and I picked sizes, etc. based on my own needs.  I researched the combination of hardware I got (OCZ Vertex 3 drives and Highpoint 2720SGL PCIe RAID controller), and I tested things pretty thoroughly before switching over to using the array as my system drive.

                   

                  But I'll be happy to help with the information I do know.  I also recommend the OCZ SSD forum, which is where I got a lot of good information.

                   

                  So far in 4 months hard daily use I haven't had a single hiccup.  It's been rock solid, and I wonder how I ever stood running my system from spinning drives before.

                   

                  -Noel

                  • 7. Re: new system with 32gb Ram.....CS5.5 using alot of scratch disk
                    Farrellart Level 3

                    I actually have a 'Lacie Big' eSata x2 bay device....I can congfigure that to use Raid0. I will throw in two 120GB SSD sata3 drives and see what happens.