hdd data speeds - Mandriva

This is a discussion on hdd data speeds - Mandriva ; I'm currently transferring about two hundred gigabytes of data from one drive in my computer to another. Why is it that with two 3 Gbit/s, 7200 SATA drives, moving data from one to the other maxes out around 45 MiB/s? ...

+ Reply to Thread
Results 1 to 8 of 8

Thread: hdd data speeds

  1. hdd data speeds

    I'm currently transferring about two hundred gigabytes of data from one
    drive in my computer to another.

    Why is it that with two 3 Gbit/s, 7200 SATA drives, moving data from one
    to the other maxes out around 45 MiB/s?

    This machine has an Intel E8400 processor and 4G RAM. I would expect
    transfers between drives to fly. Is this the sort of speed I should
    expect?

    --
    "Because all you of Earth are idiots!"
    ¯`·.¸¸.·´¯`·-> freemont© <-·´¯`·.¸¸.·´¯

  2. Re: hdd data speeds

    freemont wrote:
    > I'm currently transferring about two hundred gigabytes of data from one
    > drive in my computer to another.
    >
    > Why is it that with two 3 Gbit/s, 7200 SATA drives, moving data from one
    > to the other maxes out around 45 MiB/s?
    >
    > This machine has an Intel E8400 processor and 4G RAM. I would expect
    > transfers between drives to fly. Is this the sort of speed I should
    > expect?
    >


    45MB/s is about right. Drive read/write speed is a lot slower than SATA
    II bandwidth.

    Check out the hard drive test charts on Tom's Hardware web site. Its an
    eye opener.

  3. Re: hdd data speeds

    on Monday 10 November 2008 15:48
    in the Usenet newsgroup alt.os.linux.mandriva
    Peaceful Bill wrote:

    > freemont wrote:
    >> I'm currently transferring about two hundred gigabytes of data from one
    >> drive in my computer to another.
    >>
    >> Why is it that with two 3 Gbit/s, 7200 SATA drives, moving data from one
    >> to the other maxes out around 45 MiB/s?
    >>
    >> This machine has an Intel E8400 processor and 4G RAM. I would expect
    >> transfers between drives to fly. Is this the sort of speed I should
    >> expect?
    >>

    >
    > 45MB/s is about right. Drive read/write speed is a lot slower than SATA
    > II bandwidth.
    >
    > Check out the hard drive test charts on Tom's Hardware web site. Its an
    > eye opener.


    You can measure your drive's performance with "hdparm -tT /dev/xxx".
    Replace "xxx" with "sda", "hdb", or whatever.


    --
    sig goes here...
    Peter D.

  4. Re: hdd data speeds

    freemont wrote:

    > I'm currently transferring about two hundred gigabytes of data from one
    > drive in my computer to another.
    >
    > Why is it that with two 3 Gbit/s, 7200 SATA drives, moving data from one
    > to the other maxes out around 45 MiB/s?
    >

    The 3GBit are only interface speed - you may get it for transferring from or
    to the harddrive cache, but certainly not for a large transfer.

    > This machine has an Intel E8400 processor and 4G RAM. I would expect
    > transfers between drives to fly. Is this the sort of speed I should
    > expect?
    >

    The real speed depends upon data density and speed of the platter, and count
    of platters in a drive. That's why there are still 15kRpm drives, but you
    don't want them for a desktop.

  5. Re: hdd data speeds

    freemont wrote:
    > I'm currently transferring about two hundred gigabytes of data from one
    > drive in my computer to another.
    >
    > Why is it that with two 3 Gbit/s, 7200 SATA drives, moving data from one
    > to the other maxes out around 45 MiB/s?
    >
    > This machine has an Intel E8400 processor and 4G RAM. I would expect
    > transfers between drives to fly. Is this the sort of speed I should
    > expect?


    Bear in mind that Linux normally ships with DMA disabled, due to
    problems on a few old pieces of hardware.

    Check hard drive capabilities with hdparm -I /dev/sda
    or whatever your device is, as root.

    man hdparm
    for more into.

    Cheers!

    jim b.


    --
    UNIX is not user unfriendly; it merely
    expects users to be computer-friendly.

  6. Re: hdd data speeds

    Jim Beard wrote:
    > freemont wrote:
    >> I'm currently transferring about two hundred gigabytes of data from
    >> one drive in my computer to another.
    >>
    >> Why is it that with two 3 Gbit/s, 7200 SATA drives, moving data from
    >> one to the other maxes out around 45 MiB/s?
    >>
    >> This machine has an Intel E8400 processor and 4G RAM. I would expect
    >> transfers between drives to fly. Is this the sort of speed I should
    >> expect?

    >
    > Bear in mind that Linux normally ships with DMA disabled, due to
    > problems on a few old pieces of hardware.
    >
    > Check hard drive capabilities with hdparm -I /dev/sda
    > or whatever your device is, as root.
    >
    > man hdparm
    > for more into.
    >
    > Cheers!
    >
    > jim b.
    >
    >



    Not at all. Unless both the drives are relatively new, 45Mbs is about
    right.

  7. Re: hdd data speeds

    On Mon, 10 Nov 2008 20:21:40 -0500, Jim Beard writ:

    > freemont wrote:


    >> Why is it that with two 3 Gbit/s, 7200 SATA drives, moving data from
    >> one to the other maxes out around 45 MiB/s?


    > Bear in mind that Linux normally ships with DMA disabled, due to
    > problems on a few old pieces of hardware.
    >
    > Check hard drive capabilities with hdparm -I /dev/sda or whatever your
    > device is, as root.
    >
    > man hdparm
    > for more into.


    I tried to enable 32-bit support on one of the drives, but it didn't take.
    Is it because hdparm is for IDE drives? Should I be looking at sdparm
    instead (not currently installed)?

    [paul@lpt-20081029 nzb]$ sudo hdparm /dev/sda

    /dev/sda:
    IO_support = 0 (default)
    readonly = 0 (off)
    readahead = 256 (on)
    geometry = 60801/255/63, sectors = 976773168, start = 0


    [paul@lpt-20081029 nzb]$ sudo hdparm -Tt /dev/sda

    /dev/sda:
    Timing cached reads: 13344 MB in 1.99 seconds = 6703.77 MB/sec
    Timing buffered disk reads: 276 MB in 3.02 seconds = 91.44 MB/sec

    [paul@lpt-20081029 nzb]$ sudo hdparm -c1 /dev/sda

    /dev/sda:
    setting 32-bit IO_support flag to 1
    HDIO_SET_32BIT failed: Invalid argument
    IO_support = 0 (default)


    --
    "Because all you of Earth are idiots!"
    ¯`·.¸¸.·´¯`·-> freemont© <-·´¯`·.¸¸.·´¯

  8. Re: hdd data speeds

    On Tue, 11 Nov 2008 02:41:27 +0000, freemont wrote:

    > On Mon, 10 Nov 2008 20:21:40 -0500, Jim Beard writ:
    >
    >> freemont wrote:

    >
    >>> Why is it that with two 3 Gbit/s, 7200 SATA drives, moving data from
    >>> one to the other maxes out around 45 MiB/s?


    The transfer rate stated is the maximum (peak) rate that the drive can
    reach. Sustained rates will depend on the bus and possibly on the memory
    management.

    >> Bear in mind that Linux normally ships with DMA disabled, due to
    >> problems on a few old pieces of hardware.


    Nearly all modern Linux distros ship with DMA enabled, and allow the user
    to turn it off at boot with the ide=nodma boot parameter.

    >> Check hard drive capabilities with hdparm -I /dev/sda or whatever your
    >> device is, as root.
    >>
    >> man hdparm
    >> for more into.

    >
    > I tried to enable 32-bit support on one of the drives, but it didn't
    > take. Is it because hdparm is for IDE drives? Should I be looking at
    > sdparm instead (not currently installed)?


    Yes, you need sdparm to set parameters on SATA drives.

+ Reply to Thread