5 Replies Latest reply on Jun 19, 2010 8:24 AM by Scott Chichelli

    Impact of SATA III - Especially for RAID

    Druyan Level 1

      Hello,

       

      I am wondering what difference in throughput/speed SATA III will bring to RAID arrays...

      for example, will a 6 x 1T SATA III RAID (any level) be as fast as a 12 x 1T SATA II RAID (comparable level).

       

      The practical reason for my question is this:  to invest in 12 SATA II discs and a SATA II RAID controller now,

      or wait 6 months for more SATA III RAID controllers (and discs) to hit the markets.

       

      The motherboards I am looking at only support 2 SATA III discs... OK for a RAID 0, but I am looking for RAID 3/5/etc. as well.

       

      I am keeping a couple of my PCIe slots empty and waiting...

       

      Thanks!

      Druyan

        • 1. Re: Impact of SATA III - Especially for RAID
          Harm Millaard Level 7

          Don't hold your breath with the expectation that performance will double. Maybe if boards come out with only SATA III connectors, but then your Raid choice will be limited. With new Raid controllers, the limiting factor will still be the PCIe bus, unless new controllers go from PCIe 8x to PCIe 16x.

          1 person found this helpful
          • 2. Re: Impact of SATA III - Especially for RAID
            Bill Gehrke Adobe Community Professional & MVP

            Druyan wrote:

             

            Hello,

             

            I am wondering what difference in throughput/speed SATA III will bring to RAID arrays...

            for example, will a 6 x 1T SATA III RAID (any level) be as fast as a 12 x 1T SATA II RAID (comparable level).

             

            .

             

            Thanks!

            Druyan

            The answer to that question is absolutely, definitely NO!  The difference in the maximum sustained transfer rates between the newer SATA III drives and the current SATA II drives will possibly be only slightly improved.

            1 person found this helpful
            • 3. Re: Impact of SATA III - Especially for RAID
              Druyan Level 1

              Thanks, guys for bursting my bubble...

               

              Well, what about the new PCIe 3, that keeps getting delayed... when that finally comes out (supposedly later this year), and when other hardware catches up... that should make quite a difference, shouldn't it?

              • 4. Re: Impact of SATA III - Especially for RAID
                Bill Gehrke Adobe Community Professional & MVP

                That should make a difference--for very large array's, or maybe larger and fast SSD's will come down in price, but it does not change the sustained transfer rate of a 7200 rpm disk drive which is the major bottleneck with hard disk drives.. I saw some place a while back that unless you get 12 to 16 drives on an array, only then will the faster transfer rate of SATA III drives pay off.  Now there is a real advantage to this newer generation of SATA III drives in that typically they are putting larger cache's on these newer drives and that has possibilities of improving performance for some software applications.

                • 5. Re: Impact of SATA III - Especially for RAID
                  Scott Chichelli Level 3

                  that was Erics posts or maybe mine.

                   

                  until you hit 6 or more drives (the more you add the better it gets) they are very close in numbers.

                  2 drive raid 0 onboard 196 intel sas (sata3) 215

                  4 drive raid 0 onboard 364  Intel SAS (sata 3) 429

                  4 drive raid 5 onboard 296   Intel sas (sata 3) 315

                   

                  raid 5 or 6 etc is what most people would run with multiple drives like that

                   

                  8 drive raid 5 :-)

                   

                  Intel SAS RS2PI080 8 Port controller with 512 DDR2 Ram

                  8x WD VelociRaptor 600 GB, SATA 6 Gb/s, 32 MB Cache, 10,000 RPM

                  8 Drive Raid 5 - 745MB/s read 735MB/s Write

                   

                  8x WD 1TB SATA 6 Gb/s, 64 MB Cache, 7200 RPM

                  8 Drive Raid 5 - 703.8MB/s read 670MB/s Write

                  Scott

                  ADK