SCSI adaptec 19160 speed - 2.6.14-rt13 - Q for scsi experts

From: art (art_at_usfltd.com)
Date: 11/30/05

  • Next message: Andi Kleen: "Re: Linux 2.6.15-rc3" 
    Date:	Tue, 29 Nov 2005 19:36:44 -0600
To: <linux-kernel@vger.kernel.org>

    SCSI adaptec 19160 speed - 2.6.14-rt13 - Q for scsi experts

    Attached scsi disk sda at scsi0, channel 0, id 1, lun 0
      Vendor: COMPAQ Model: BF14688286 Rev: HPB3
      Type: Direct-Access ANSI SCSI revision: 03
    scsi0:A:2:0: Tagged Queuing enabled. Depth 64
    target0:0:2: Beginning Domain Validation
    target0:0:2: wide asynchronous.
    target0:0:2: FAST-80 WIDE SCSI 160.0 MB/s DT (12.5 ns, offset 63)
    target0:0:2: Ending Domain Validation
    SCSI device sdb: 286749488 512-byte hdwr sectors (146816 MB)
    SCSI device sdb: drive cache: write through
    SCSI device sdb: 286749488 512-byte hdwr sectors (146816 MB)
    SCSI device sdb: drive cache: write through
    sdb: sdb1
    Attached scsi disk sdb at scsi0, channel 0, id 2, lun 0
      Vendor: COMPAQ Model: BF14688286 Rev: HPB3
      Type: Direct-Access ANSI SCSI revision: 03
    scsi0:A:5:0: Tagged Queuing enabled. Depth 64
    target0:0:5: Beginning Domain Validation
    target0:0:5: wide asynchronous.
    target0:0:5: FAST-80 WIDE SCSI 160.0 MB/s DT (12.5 ns, offset 63)
    target0:0:5: Ending Domain Validation
    SCSI device sdc: 286749488 512-byte hdwr sectors (146816 MB)
    SCSI device sdc: drive cache: write through
    SCSI device sdc: 286749488 512-byte hdwr sectors (146816 MB)
    SCSI device sdc: drive cache: write through
    sdc: sdc1
    Attached scsi disk sdc at scsi0, channel 0, id 5, lun 0

    # hdparm -tT /dev/sdb
    /dev/sdb:
    Timing cached reads: 2316 MB in 2.00 seconds = 1157.90 MB/sec
    Timing buffered disk reads: 268 MB in 3.00 seconds = 89.26 MB/sec
    # hdparm -tT /dev/sdc

    /dev/sdc:
    Timing cached reads: 2512 MB in 2.00 seconds = 1255.49 MB/sec
    Timing buffered disk reads: 268 MB in 3.00 seconds = 89.32 MB/sec

    # hdparm -tT /dev/sdb & hdparm -tT /dev/sdc &
    [1] 3314
    [2] 3315

    /dev/sdb:
    /dev/sdc:
    Timing cached reads: Timing cached reads: 1228 MB in 2.00 seconds = 613.88 MB/sec
    1316 MB in 1.99 seconds = 659.73 MB/sec
    Timing buffered disk reads: Timing buffered disk reads:
    174 MB in 3.00 seconds = 57.91 MB/sec
    170 MB in 3.05 seconds = 55.75 MB/sec
    ------------------------------------------------------------------------------------------

    pci is 66Mhz theoretical throuhput ~ 250MB/s

    controller adaptec asc-19160
    discs are 146GB-15krpm-cheetah

    one disc transfer 89MB/s

    adaptec speed with 2 disc on one channel = 57.91+55.75 = 113.66MB/s

    71% of 160MB/s channel speed i expected ~90%

    any clue?

    xboom
    -
    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to majordomo@vger.kernel.org
    More majordomo info at http://vger.kernel.org/majordomo-info.html
    Please read the FAQ at http://www.tux.org/lkml/

  • Next message: Andi Kleen: "Re: Linux 2.6.15-rc3"

    Relevant Pages