11 Replies Latest reply on Dec 19, 2012 1:59 PM by Baz R

    Best Use of one SSD  for cache drives

    Jan Janowski Level 1

      Hello...  Months ago I added two Physical  Momentus XT drives to be used  as Cache only drives:  One as a Cache disk, and one as a Cache Database disk.  This is the only function these drives do...

      Doing this really sped up large session loads...

       

      I'm going to be getting one SSD soon, and was wondering.... Of the Two Caches....  Cache, or Cache Database...

      Which would benifit the most from an SSD over a hybrid hard drive??

       

      Seeing that the Controller is a 3Gb/sec controller only....  That's why I used two separate Cache disks..

       

      Now that I'll have the benifit of a SSD speed over a Hybrid Drive (Faster Reads only)... Should I combine both in the SSD or still keep them separate?

       

      Thanks!    Jan

        • 1. Re: Best Use of one SSD  for cache drives
          Harm Millaard Level 7

          Jan,

           

          Good question for your situation.

           

          Media cache files are sometimes large, media cache database files are always small (1 KB). Also the number of Media cache files is much larger than Media cache database files.

           

          I have never tried it out, but on the one hand the sustained read speed of an SSD and the number of IOPS plead for using the SSD for Media cache, but that means the media cache database pointers suffer from the much lower IOPS of a hybrid disk and the slower access time.  If you reverse this, then the media cache, with the larger files does not suffer from IOPS as much, but there are more files to read, so access time can make a difference. I can't really give you an answer. Try it out and you will know. Once you have your test results, please let us know.

          • 2. Re: Best Use of one SSD  for cache drives
            Jan Janowski Level 1

            Thank you, Harm...

             

            I was wondering that exact thing.... but then the 2nd part of the question....   Would it benifit by putting both on the SSD vs. two separate drives, or is the controller's 3Gb/sec then going to be the limitation???

             

            This should reduce the throughput of each to maybe 40%, but that may still exceed the throughput of 2 hybrid drives.

             

            Decisions, Decisions!

            • 3. Re: Best Use of one SSD  for cache drives
              Jan Janowski Level 1

              I have replaced 2 Momentus XT drives (One with Media Cache, and other with Cache Database)  with 1 Samsung 840 SSD, which has 2 folders: CS6 Cache, and CS6 Cache Database.

               

              Prior to pulling the drives, I tested the time it took to load a 45 min 1080i AVCHD session that had over 400 scenes, 600 2k JPEG's and about 25 pieces of music.  From clicking on the session to load, until "All Media Loaded" took about 34 seconds (This is with the Cache's on separate Hard drives).  Shut system down, pulled the two drives, added the one SSD drive, power up, formatted the drive and added the above mentioned folders...  Then launched PPRO and pointed the Media Cache and Cache Database at these new locations... Then launched the 45 min session, and walked away while it created the data locations, peek files, etc, to the new SSD Cache Drive folders.

               

              When It was finished, I closed, rebooted the system, Launched PPRO, and timed from the Click on the session, till the end of "All Media Loaded"...     19 seconds...

               

              Will be watching this intently......  

               

              EDIT:   SO far, I'm happy with the change.... I am interested in anyone else who has done this sort of thing before.... and in paticular, if you found any negatives of putting both cache's on the same physical drive, even if it is a SSD....

               

              I did find my prior notes, and going from Cache's on raid (Different directory than media, though media was on same raid) to separate Momentus XT Drives decreased load time of this same 45 min project by ~ 15 seconds..

               

              $$$ Available was only enough for one SSD, and I'm not certain if multiple SSD's for cache's would be worth the $$.... Which is pretty much why I posted here....

               

              Looking forward to your comments...

              • 4. Re: Best Use of one SSD  for cache drives
                Jan Janowski Level 1

                I'm new to SSD's, but used the latest version of their "Magician" SSD Utiltiy to verify firmware (Current) and "Optomise" the SSD...

                Afterward, shut dowtn, re-booted and re-ran my benchmark 45 min project...   Same 19 Seconds from click to "All Media Loaded"....

                So I'm as good as it can get for now....  Or so it seems....

                • 5. Re: Best Use of one SSD  for cache drives
                  Alex - DV411 Level 2

                  I did find my prior notes, and going from Cache's on raid (Different directory than media, though media was on same raid) to separate Momentus XT Drives decreased load time of this same 45 min project by ~ 15 seconds..

                  From about 50 seconds down to 34, did I get it right?  What type of a RAID is it?  (Number of drives, type of drives, RAID level, connection type, controller type.)

                   

                  Thanks for doing these tests - really useful.  I always thought dedicating stand-alone volumes or disks to caching is impractical, however in your case it clearly is (practical): even if you had an option of adding two more disks to your array, it may or may not have improved the loading speeds as much as it did in your case.

                  • 6. Re: Best Use of one SSD  for cache drives
                    Jan Janowski Level 1

                    The Raid 0 is only a 2 drive array... I've been experimenting for months trying to get the best bang for the buck.  I don't envy the idea of a new system.  Money is very tight right now, so adding some $ to the system is do-able, but not a new system... (Let's just say I have Good Taste when it comes to a new system... $$$$$.

                    At Present My 6 year old system uses:

                     

                    C: OS Drive 320mb/sec 15K SCSI

                    F: Sata Raid 0 for media

                    E: Sata drive for sessions

                    H: Sata SSD for Cache

                    I:  Sata drive for Previews

                    D; & G: are DVD R/W  BR R/W

                     

                    Dual Quad Core Xeon Server.  Started out life as XP Pro and 4Gb/Ram, Now W7-64 & 24Gb Ram  & Cuda Display   The SATA (and drives, except for SSD) are only 3Gb/sec due to age of system, and that seems to be the reason why individual drives work better than doubling up on a raid..

                    • 7. Re: Best Use of one SSD  for cache drives
                      JCschild Level 3

                      there is no point to seperate cache drives

                      we also bechmarked SSDs as OS, As Sepereate Cache etc etc.. pointless as far as actual performance gains.

                      we even did a 4 drive raid 0 SSD drive way overkill. average workflows cant come close to needing that kinid of thruput.

                      heavy Animation maybe.

                       

                      Scott

                      ADK

                      • 8. Re: Best Use of one SSD  for cache drives
                        Jan Janowski Level 1

                        Good to hear others have tried this... GOOD!  Therefore, let me ask some questions... Based upon Questions I've been wondering about....

                         

                        When I had media & cache(s) on same raid0, it suffered, and putting caches on separate momentus XT drives helped. (Note this was back before the latest Intel chipset drivers, which helped also.  I had one Seagate XTV1 and one XTV2, and put the more intense cache on the V2 XT, as it had greater Read SSD Cache, and that also seemed to help ... Again, these drives and controller are 3Gb/sec SATA.... 

                         

                        Going from cache & Media on Raid0, to Media on Raid0 and Caches on 2 Drives, imporoved the 'big project' load times, which seems to be the best determination of Cache Preformance that I could come up with at the time.

                        Going from Cache(s) on 2 separate drives, to both on one SSD Improved load times as well...

                         

                        With Software (PPRO) Changing, Me attemping to find a faster implementation of large project load by jockying drives and cache locations around, and things like Intel Chipset drivers, NVidia Drivers, (I'm going to make the wild assumption that W7-64 OS & Driver Updates will have minimum impact to this ??? ) .....

                        ALL of this happening at the same time, can cause one to begin to doubt their sanity.... Is it no wonder that it becomes hard to comfortably determine that the proper changes should be made, and even harder to prove with a test???

                         

                        So Alex & Scott (And Others) If you have some time.... I'd appreciate to know more about what you found with many configurations, and what tests you did to confirm those changes....

                         

                        Was my large project load timing a viable test for Cache configuration testing?

                        • 9. Re: Best Use of one SSD  for cache drives
                          Alex - DV411 Level 2

                          So Alex & Scott (And Others) If you have some time.... I'd appreciate to know more about what you found with many configurations, and what tests you did to confirm those changes....

                          The limited testing I did was on small projects with fairly fast drives.  Clearly not the case here.

                          Was my large project load timing a viable test for Cache configuration testing?

                          I am positive of it. It may be an indication that very large and complex projects (lots of layers, small items, dynamic linking, etc.) benefit from a separate dedicated volume for media caching and database.  Alternately, this may be true for smaller projects on older systems with slower disk I/O.

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                          • 10. Re: Best Use of one SSD  for cache drives
                            Jan Janowski Level 1

                            It's nice to compare notes!!!  Thanks!

                            • 11. Re: Best Use of one SSD  for cache drives
                              Baz R Level 3

                              Hi,

                               

                              Ive been using a Raid 0 3x Drive Setup for Temp & Media Cache Files for a While now. I am using 3x 320gb Samsung F4 on a Raid card with a 2gb memory.

                               

                              I had the drives as spares and had the space so decided to try it, and it did improve access of files.