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  • SSD seems slow

    Hi,

    just bought a Kingston SSD 120GB. Installed Ubuntu 14.04 on it, but i think the drive is slow. Booting takes about 30-40 seconds and after the desktop appears i cant start anything for about 20 seconds. Also in games like Witcher 2, i have the feeling that the textures wont load fast enough.

    My Specs:
    Code:
    Ubuntu 14.04 64Bit
    AMD Athlon 64 X2 Dual Core 6400+
    Asus M2N32-SLI Deluxe/Wireless Edition
    6 GIG Ram DDR2 
    Geforce GTX 750 
    Kingston SSD 120GB
    I know my board doesnt support AHCI Mode, but is this really such a huge difference? When i test the drive i get these results:

    Code:
    sudo hdparm -tT /dev/sda
    
    /dev/sda:
     Timing cached reads:   2784 MB in  2.00 seconds = 1393.34 MB/sec
     Timing buffered disk reads:  64 MB in  3.05 seconds =  20.97 MB/sec

  • #2
    Those results are really, really shitty. My five years old laptop HDD beats it.

    Timing cached reads: 6830 MB in 2.00 seconds = 3416.28 MB/sec
    Timing buffered disk reads: 182 MB in 3.00 seconds = 60.58 MB/sec

    Not using AHCI either, native driver.

    Comment


    • #3
      Okey, so i know for sure its way too slow. Now to find how to fix this :/

      Comment


      • #4
        Return it and buy a HDD

        Comment


        • #5
          Switched back to my HDD and with it i get these results:

          Code:
          /dev/sda:
           Timing cached reads:   2604 MB in  2.00 seconds = 1303.68 MB/sec
           Timing buffered disk reads: 228 MB in  3.02 seconds =  75.41 MB/sec
          Not much of a difference to me

          Comment


          • #6
            Something seriously wrong there.

            here's mine (OCZ Vertex 4)

            Code:
            [root@com1 ~]# hdparm -tT /dev/sda
            
            /dev/sda:
             Timing cached reads:   38032 MB in  2.00 seconds = 19037.15 MB/sec
             Timing buffered disk reads: 1164 MB in  3.00 seconds = 387.43 MB/sec
            [root@com1 ~]#

            Comment


            • #7
              Your probably limited by other hardware like cpu oe motherboard (bottleneck).
              if your board does not support ACHI it must be really old so im asumming you're...
              My 7 year old motherboard has it :P

              Also make sure you dont use EXT4 on a SSD try BTRFS or something newer that supports SSD's.

              Comment


              • #8
                hdparm does not test filesystems and i see no reason why ext4 would be bad. The SATA controler is just fully outdated, you could try to get a pci-e controller instead or just replace the board.

                Comment


                • #9
                  Originally posted by pete910 View Post
                  387.43 MB/sec
                  That's very close to max throughput of a 3Gbps controller. Are you sure your SSD isn't attached to a 3Gbps SATA port? On a 6Gbps port you should see a higher result - something close to 500MB/sec.

                  Comment


                  • #10
                    As for the OP's case - Kingston SSDs are frustratingly slow but 20MB/s isn't right even for them. First thing to do: check that BIOS and SSD firmware are up to date.

                    Comment


                    • #11
                      Could you run the same test with an HDD? I bet its the disk controller ... or more precisely, the driver that drives it. FreeBSD prints out the read/write speed of each disk on dmesg. Can you check this on Linux somewhere?

                      EDIT:
                      Oh you did. Yeah it's the controller. Try to find out what the reported read/write speed is.
                      Last edited by nslay; 09-20-2014, 02:24 PM.

                      Comment


                      • #12
                        One possibility is that the drive's internal datastructures are somehow garbled and it's GC is not working right. I had this problem with a brand new Samsung EVO SSD; it had awful performance out of the box presumably because I never formatted it: all I did was add it to an MD RAID mirror

                        I fixed the issue by issuing a discard for the entire drive with the blkdiscard command, so that the internal controller knows all blocks are free. Speeds went from 20-30MB/s to near 500MB/s, even with just the simple hdparm test.

                        Do note using blkdiscard on a drive or partition will instantly destroy all data on it, no questions asked, so try it as a last resort after having backed up your data.

                        EDIT: If the drive is formatted and the filesystem has mostly free space, try running the fstrim command first.
                        Last edited by Chousuke; 09-20-2014, 04:03 PM.

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                        • #13
                          Originally posted by TheSoulz View Post
                          Also make sure you dont use EXT4 on a SSD try BTRFS or something newer that supports SSD's.
                          EXT4 supports SSDs just fine. In my experience, it has fewer issues than btrfs even. btrfs seems to have CPU usage issues crop up over time with SSDs, even with discards enabled.

                          Comment


                          • #14
                            Originally posted by Chousuke View Post
                            One possibility is that the drive's internal datastructures are somehow garbled and it's GC is not working right. I had this problem with a brand new Samsung EVO SSD; it had awful performance out of the box presumably because I never formatted it: all I did was add it to an MD RAID mirror

                            I fixed the issue by issuing a discard for the entire drive with the blkdiscard command, so that the internal controller knows all blocks are free. Speeds went from 20-30MB/s to near 500MB/s, even with just the simple hdparm test.

                            Do note using blkdiscard on a drive or partition will instantly destroy all data on it, no questions asked, so try it as a last resort after having backed up your data.

                            EDIT: If the drive is formatted and the filesystem has mostly free space, try running the fstrim command first.
                            If that's really true, SSD technology sucks (or at least that particular drive). The original poster also showed a benchmark of an HDD which points to problems elsewhere (very likely the disk controller, some of them are buggy like Promise controllers).

                            Comment


                            • #15
                              Originally posted by nslay View Post
                              If that's really true, SSD technology sucks (or at least that particular drive). The original poster also showed a benchmark of an HDD which points to problems elsewhere (very likely the disk controller, some of them are buggy like Promise controllers).
                              Just a quick Internet search for Promise controllers (this is an example, not necessarily the original poster's problem):
                              http://ubuntuforums.org/showthread.php?t=905446

                              I've also seen them mentioned a lot on FreeBSD mailing lists.

                              Comment

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