Re: Compact Flash performance...

Bartlomiej Zolnierkiewicz
2007-05-30T22:44:41Z

Hi,

Since you are using libata ata_piix driver and not IDE piix one
Jeff and/or Alan are the right people to ask this question...

Anyway...

On Thursday 31 May 2007, Daniel J Blueman wrote:
> I have a SanDisk Extreme IV 4GB CF card, capable of 40MB/s read, but
> am seeing 30MB/s read [1], connected directly to the IDE bus on my
> ICH8 controller.
>
> How can I find out if this would be a timing or configuration issue?
> On 2.6.20.5 [2], the 120nS timing looks to be right [3], but perhaps

multi-word DMA cycle timing seems to be configured OK

Shouldn't really matter since it is for multi-word DMA transfers
and this device is using UDMA transfers.

> no multi-word transfer is hurting here...alas, it can't be enabled
> with the libata subsystem and 'hdparm -m', so what else?

-m is for multi sector PIO transfers and probably won't help here

Everything (except harmless "abnormal status" garbage) seems fine.

Where does the max 40MB/s come from? Were you able to get this device to
work with this speed using some other controller and/or other OS-es?

Thanks,
Bart

> Daniel
>
> --- [1]
>
> # hdparm -t /dev/sdb
> /dev/sdb:
> Timing buffered disk reads: 94 MB in 3.05 seconds = 30.79 MB/sec
>
> --- [2]
>
> ata7: PATA max UDMA/100 cmd 0x000000000001bc00 ctl 0x000000000001b882
> bmdma 0x000000000001b400 irq 17
> ata7.00: CFA: SanDisk SDCFX-4096, HDX 4.04, max UDMA/66
> ata7.00: 8027712 sectors, multi 0: LBA
> ata7.00: configured for UDMA/66
> ATA: abnormal status 0x7F on port 0x000000000001b807
> scsi 6:0:0:0: Direct-Access ATA SanDisk SDCFX-40 HDX PQ: 0 ANSI: 5
> SCSI device sdb: 8027712 512-byte hdwr sectors (4110 MB)
> sdb: Write Protect is off
> sdb: Mode Sense: 00 3a 00 00
> SCSI device sdb: write cache: disabled, read cache: enabled, doesn't
> support DPO or FUA
> SCSI device sdb: 8027712 512-byte hdwr sectors (4110 MB)
> sdb: sdb1
> sd 6:0:0:0: Attached scsi removable disk sdb
>
> --- [3]
>
> # hdparm -I /dev/sdb
>
> /dev/sdb:
>
> CompactFlash ATA device, with removable media
> Model Number: SanDisk SDCFX-4096
> Serial Number: 116802D2807J3335
> Firmware Revision: HDX 4.04
> Standards:
> Supported: 4
> Likely used: 4
> Configuration:
> Logical max current
> cylinders 7964 7964
> heads 16 16
> sectors/track 63 63
> --
> CHS current addressable sectors: 8027712
> LBA user addressable sectors: 8027712
> device size with M = 1024*1024: 3919 MBytes
> device size with M = 1000*1000: 4110 MBytes (4 GB)
> Capabilities:
> LBA, IORDY(may be)(cannot be disabled)
> Standby timer values: spec'd by Vendor
> R/W multiple sector transfer: Max = 4 Current = 0
> DMA: mdma0 mdma1 mdma2 udma0 udma1 udma2 udma3 *udma4
> Cycle time: min=120ns recommended=120ns
> PIO: pio0 pio1 pio2 pio3 pio4
> Cycle time: no flow control=120ns IORDY flow control=120ns
> Commands/features:
> Enabled Supported:
> Write cache
> * CFA feature set
> --
> Daniel J Blueman