On Mon, 2007-01-15 at 18:13 +0900, Tejun Heo wrote: > kenneth johansson wrote: > > I changed my bios setting for SATA from IDE to AHCI. > > > > This resulted in some "interesting" read throughput. > > > > plots can be found at http://kenjo.org/~ken/sata/ > > The plots was done on a live disk so some noise is expected but in the > > ahci mode the throughput get stuck at 17 MB way to much. > > It's probably not an ahci problem but more of NCQ implementation problem > in the drive firmware. Please report the result of 'hdparm -I /dev/sdX' > and try adjust queue depth and see what happens. > > http://linux-ata.org/faq.html > It was, when I turn of NCQ with "echo 1 > /sys/block/sda/device/queue_depth" I get the same performance as when the BIOS is set to IDE. I though that NCQ was intended to increase performance ?? also the disk is a Westen Digital raptor and it's probably the most benchmarked drive one could get so I was not expecting a problem with the drive. ------- ATA device, with non-removable media Model Number: WDC WD1500ADFD-00NLR1 Serial Number: WD-WMAP41269747 Firmware Revision: 20.07P20 Standards: Used: ATA/ATAPI-7 published, ANSI INCITS 397-2005 Supported: 7 6 5 4 Configuration: Logical max current cylinders 16383 16383 heads 16 16 sectors/track 63 63 -- CHS current addressable sectors: 16514064 LBA user addressable sectors: 268435455 LBA48 user addressable sectors: 293046768 device size with M = 1024*1024: 143089 MBytes device size with M = 1000*1000: 150039 MBytes (150 GB) Capabilities: LBA, IORDY(can be disabled) Queue depth: 32 Standby timer values: spec'd by Standard, with device specific minimum R/W multiple sector transfer: Max = 16 Current = 16 Recommended acoustic management value: 128, current value: 254 DMA: mdma0 mdma1 mdma2 udma0 udma1 udma2 udma3 udma4 udma5 *udma6 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: * SMART feature set Security Mode feature set * Power Management feature set * Write cache * Look-ahead * Host Protected Area feature set * WRITE_BUFFER command * READ_BUFFER command * NOP cmd * DOWNLOAD_MICROCODE Power-Up In Standby feature set * SET_FEATURES required to spinup after power up SET_MAX security extension * Automatic Acoustic Management feature set * 48-bit Address feature set * Device Configuration Overlay feature set * Mandatory FLUSH_CACHE * FLUSH_CACHE_EXT * SMART error logging * SMART self-test * General Purpose Logging feature set * SATA-I signaling speed (1.5Gb/s) * Native Command Queueing (NCQ) * Host-initiated interface power management * Phy event counters DMA Setup Auto-Activate optimization * Software settings preservation * SMART Command Transport (SCT) feature set * SCT Long Sector Access (AC1) * SCT LBA Segment Access (AC2) * SCT Error Recovery Control (AC3) * SCT Features Control (AC4) * SCT Data Tables (AC5) unknown 206[12] Security: Master password revision code = 65534 supported not enabled not locked frozen not expired: security count not supported: enhanced erase Checksum: correct - To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
