4 Replies Latest reply on Oct 20, 2010 9:42 AM by canoli99

    AE CS4 SSD Scratch/Cache Question

    canoli99 Level 1

      sorry, I know this has been "done to death" here but I can't find good info about the setup I've got.

       

      It's a Win7 Pro 64-bit machine. I have an SSD - partitioned for boot/apps (C:\) and the other partition for misc scratch space and caches.

       

      I've read you can use your SSD for OS/Apps and for scratch/cache space and it will be fine - not quite as good as a separate SSD for cache space but still faster than mechanical drives.

       

      Is this true? I suppose what matters most is how much RAM is available - I've got 12G.

       

      The Windows folks say not to mess with the paging file; they don't recommend "no paging file" for the boot drive, or even moving it. But of course "Windows folks" aren't necessarily the best judges of performance in the CSs.

       

      Is it okay to use the same SSD for the OS/Apps and the caches? Does having a separate partition for them help or hurt at all?

       

      I can move the caches (and the paging file if you recommend it) to a relatively fast (new) 7200K mechanical disk.

       

      Thanks for any thoughts, advice you can share - I appreciate it!

        • 1. Re: AE CS4 SSD Scratch/Cache Question
          Mylenium Most Valuable Participant

          Is it okay to use the same SSD for the OS/Apps and the caches?

           

          Depends on how quickly you want to ruin your SSD... To the point: SSDs are sensitive to writing operations as they only allow so and so many operations per cell before those little capacitors blow out. These values are far, far below what magnetic disk drives can handle. Now that is still not a problem for your average day to day stuff - the controller chip in the SSD will manage to not overwrite the same cells but use empty "fresh" areas - for as long as this is possible. After that, it begins to overwrite occupied cells and during a normal lifecycle of a computer (3 to 4 years) that is usually enough. Now here's the deal: When you are dealing with video, you are dealing with either huge files (clips) or gigazillions of smaller files (image sequences). This means your tiny little cells would get overwritten quite often, quickly exhausting their lifecycles. And what then? If even one of them goes kaput without the controller chip doing its magic, with a critical file or an important clip getting damaged in the process you are FUBARd and risk losing all your work. That is particulalrly true, since SSDs are small compared to conventional harddisks and there is simply not much room for storing backup info. So to make a long story short: Don't do it! Leave your caches on the second drive and give your SSD a better life! I would even go as far as minimizing the system page file on the SSD and giving it more room on the mechanical disk therefore. Also note, that on many "home user" SSDs writing speed is not necessarily so great, so even if the other considerations wouldn't matter, for a cache system of huge amounts of data it might not be the best option...

           

          Mylenium

          • 2. Re: AE CS4 SSD Scratch/Cache Question
            canoli99 Level 1

            I thought TRIM was supposed to prevent all that degradation you refer to, or at least slow it down considerably. But you didn't mention TRIM or the garbage collection routines that all SSDs use.

             

            I've got a fast SSD so I'm not worried about write speeds. But I am worried about shortening the life through repeated reads/writes. I guess I still don't quite understand the media cache's purpose in AE (and the rest of the Prod Prem suite). Don't the programs only use it when the RAM is maxed out?

             

            Anyway, I'm happy extend my OS partition and delete the Caches partition, move the scratch/media caches to a mechanical drive, if you think that's the best way to go. But maybe TRIM figures into the story here, as I understand it preserves the life of SSDs.

             

            Thanks for your reply!

            • 3. Re: AE CS4 SSD Scratch/Cache Question
              Mylenium Most Valuable Participant

              canoli99 wrote:

               

              I thought TRIM was supposed to prevent all that degradation you refer to, or at least slow it down considerably. But you didn't mention TRIM or the garbage collection routines that all SSDs use.

               

              You can't defeat the physics - a capacitor can only be charged so and so many times before its electrical contacts are unable to bridge the tiny gap and produce a valid charged/ uncharged differential voltage because due to use the gap either becomes too large or in reverse, short-circuits. Of course there are ways to minimize this and there is a difference between multi-state cells vs. single state cells, but eventually each of them will suffer this. It's really a simple matter of the current materials used in the chips degrading through use. Of course this wil lget better and better with each generation of drives, but for the time being it is a concern - just like USB sticks break down after X transfers, so will your disks. It's a mathematical certainty. The only question is whether you will ever reach that point in time to notice it. As for your otehr questions - the media cache only comes into play when dealing with compressed sources. in order to more quickly decode and access them, AE stores indexing info and partialyl also decodes these files. This allows the program to reconstruct the actual image and audio faster for previews and rendering. This is a persistent mechanism and unrelated to actual RAM usage. RAM usage only effects the conventional disk cache and of course your system swap file, but in the latter case even on a freshly booted system, there wil lalways be a minimum page file. It's just how Windows works and it cannot go without it, even if the page file is just reserved disk space and never actualyl used... Whether you use the AE cache is of course up to you and would hugely depend on what kind of projects you work with.

               

              Mylenium

              • 4. Re: AE CS4 SSD Scratch/Cache Question
                canoli99 Level 1

                "So to make a long story short: Don't do it! Leave your caches on the second drive and give your SSD a better life!"

                 

                okay Myl, thanks.

                 

                So I'll follow that advice and move my scratch disks to an internal drive.

                 

                Last question is about the working files - whether to import them onto the SSD on a project-by-project basis. Would you do that?

                They are now all on an internal drive, a 1TB 7200K HDD.  When starting a new AE project, should I copy the source files to the SSD?

                Will AE work faster with the various clips and stills on an SSD? Or should I just leave them on the mechanical drive?

                 

                I'm trying to make AE run as fast as possible. My system has 12G of RAM, a 6-core processor and an SSD.

                So far all I've got on the SSD is the OS and my apps, and I've still got close to 80G of free space. I'd like CS4 to exploit that space if possible.

                 

                (btw, I assume for rendering it doesn't matter where you render to - is that right? as  long as it's not a USB drive of course.)

                 

                Thanks again for all your help Mylenium, I appreciate it very much!

                -Richard