5 Replies Latest reply on Dec 2, 2014 3:25 PM by johnt53984649

    Reading while Writing on SSDs vs HDDs

    johnt53984649 Level 2

      So, I've always heard that reading and writing to an HDD is not good, as it slows down the whole process (this is in video rendering for Premiere Pro).

      So, I know that SSDs are quite a bit different.  I'm assuming that reading and writing occurring on 1 SSD during rendering isn't going to be nearly as much of a problem as it would be happening on 1 HDD.  However, I'm unsure of this.  Am I correct in my assumption?  If not, what kind of performance degradation might occur, would it be noteworthy, and how comparable would it be to that of an HDD?

        • 1. Re: Reading while Writing on SSDs vs HDDs
          ECBowen Most Valuable Participant

          That comes down to latency and yes SSD's are very good at that since their latency is in microseconds instead of milliseconds. Mechanical hard drives are not good at that due to the latency of the mechanics.

           

          Eric

          ADK

          • 2. Re: Reading while Writing on SSDs vs HDDs
            JFPhoton Level 3

            Yes, in addition.....current high quality SATA III SSDs that have the best controllers in them  for video editing, ( like the Crucial M550, or, the more expensive Samsung 850pro), will not suffer from "fill degradation"....losing performance as the drives becomes more full. Also, the RELIABILITY ....especially on the Samsung 850 Pro....is WAY higher for the SSDs, than mechanical spinning drives.....allowing those quality SSDs to be considered for RAID 0 usage with a much lower risk.

             

            What you are getting at is the nature of the SATA interface itself......it is a "half-duplex" interface, which means it CANNOT write while READING...and vice-versa. It's like an old walkie-talkie radio....when you push the button to speak and transmit...you cannot RECEIVE anything ,until you let the button go. So, YES ,that "half-duplex" handicap is still there.....BUT, SSDs reduce its effect with their MUCH faster read and write speeds AND their drastically lower "latency", as Eric has said.

             

            There ARE places to connect storage devices, especially on the new Haswell E X 99 motherboards, which are "full duplex"...allowing reading and writing at the SAME TIME.  However, the storage devices to take advantage of this higher speed and full duplex connection currently are much more expensive than SATA devices. M.2, , SATA "Express", and PCI card storage devices can be used.....but, currently at high expense and limited capacity.

             

            With X99...one option is to take advantage of the huge amount of SATA !!! ports on the motherboard and just create RAID 0 with SSDs for storage..or, use cheaper HDDs, with a large "enterprise level" 7200rpm HDD to BACK UP the HDD RAID0 array !

            • 3. Re: Reading while Writing on SSDs vs HDDs
              johnt53984649 Level 2

              I see.  So if I were to have a drive dedicated just to reading while exporting and another drive dedicated just to writing while exporting, could I, possibly, expect any kind of performance gain?  Or, given how fast the Samsung 850 Pros are, would there no really be much of a difference if I were to have significant reading and writing occurring on the same disk?

              • 4. Re: Reading while Writing on SSDs vs HDDs
                ECBowen Most Valuable Participant

                Mechanical drives show an increase when having a drive for read and a drive for write. SSD's are so fast that increase is negligible at best.


                Eric

                ADK

                • 5. Re: Reading while Writing on SSDs vs HDDs
                  johnt53984649 Level 2

                  Okay, that's what I was hoping to hear.  Thank you everybody for the great information.