Re: Abysmal PATA IDE performance

[Stephen Clark <Stephen.Clark@seclark.us>]

Arjan van de Ven wrote:

>>> 
>>>
>>>      
>>>
>>Thanks all.
>>
>>Arjan, using combined_mode=libata and making a new ramdisk increased my 
>>xfer rate from 1.xx mb/sec to 28.xx mb/sec.
>>
>>    
>>
>
>ok that's getting somewhere
>
>  
>
>>I am curious as to why my friends dell inspiron 8200 with a 1.8ghz p4 
>>and the same drive using the same drive with FC6 and the standard ide 
>>module gets 44 to 45 mb/sec.
>>    
>>
>
>now it is going to come down to how you measure this....
>
>don't use hdparm, use something like tiobench (tiobench.sf.net);
>another setting that might be different is that scsi normally turns the
>write back cache off (safer for your data but slower) while IDE normally
>leaves at at factory default (on for cheating on benchmarks).
>For writes, this can easily explain the difference...
>
>
>  
>
Looking at the dmesg output I am a little confused, see comments below:
partial dmesg output follows:

SCSI subsystem initialized
libata version 2.00 loaded.
ata_piix 0000:00:1f.2: version 2.00
ata_piix 0000:00:1f.2: MAP [ P0 P2 IDE IDE ]
ACPI: PCI Interrupt 0000:00:1f.2[B] -> GSI 19 (level, low) -> IRQ 233
PCI: Setting latency timer of device 0000:00:1f.2 to 64
ata1: SATA max UDMA/133 cmd 0x1F0 ctl 0x3F6 bmdma 0xFFA0 irq 14
scsi0 : ata_piix
Synaptics Touchpad, model: 1, fw: 6.1, id: 0xa3a0b3, caps: 0xa04713/0x10008
input: SynPS/2 Synaptics TouchPad as /class/input/input1
ATA: abnormal status 0x7F on port 0x1F7
ata2: PATA max UDMA/100 cmd 0x170 ctl 0x376 bmdma 0xFFA8 irq 15
scsi1 : ata_piix
ata2.00: ATA-6, max UDMA/100, 117210240 sectors: LBA48
ata2.00: ata2: dev 0 multi count 16
usb 2-2: new low speed USB device using uhci_hcd and address 3
ata2.01: ATAPI, max UDMA/33
ata2.00: configured for UDMA/33 <==== why isn't this 66 or 100 ?
===============****
usb 2-2: configuration #1 chosen from 1 choice
input: Logitech USB-PS/2 Trackball as /class/input/input2
input: USB HID v1.00 Mouse [Logitech USB-PS/2 Trackball] on
usb-0000:00:1d.1-2
ata2.01: configured for UDMA/33 <=========== is this related to the
following 2 lines? ====
   Vendor: ATA       Model: HTS721060G9AT00   Rev: MC3O
   Type:   Direct-Access                      ANSI SCSI revision: 05
SCSI device sda: 117210240 512-byte hdwr sectors (60012 MB)
sda: Write Protect is off
sda: Mode Sense: 00 3a 00 00
SCSI device sda: drive cache: write back
SCSI device sda: 117210240 512-byte hdwr sectors (60012 MB)
sda: Write Protect is off
sda: Mode Sense: 00 3a 00 00
SCSI device sda: drive cache: write back
  sda: sda1 sda2
sd 1:0:0:0: Attached scsi disk sda
   Vendor: HL-DT-ST  Model: DVDRAM GMA-4082N  Rev: HJ02
   Type:   CD-ROM                             ANSI SCSI revision: 05
device-mapper: ioctl: 4.7.0-ioctl (2006-06-24) initialised:
dm-devel@redhat.com
kjournald starting.  Commit interval 5 seconds

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