Hard Drive Speed
Konstantin Svist
fry.kun at gmail.com
Thu Nov 1 02:53:06 UTC 2007
Todd Simi wrote:
> Hi,
>
> I know this may be a silly question since it probably a hardware limitation,
> but I'm running F7 and would like to know what I can do to increase the hard
> drive seek time, if anything.
>
> I have a pretty new SATA drive at 3GB/sec and it seems to have to seek longer
> than I'd expect.
>
> It's running with DMA4, AHCI, etc.
>
> The rest is an ASUS MB with a Core 2 Duo 6400 @ 2.4 Mhz & 2GB Ram @ 800Mhz.
>
> Are there any setting from the standard that by help?
>
> here's the hdparm output
>
> [root at localhost ~]# hdparm -tT /dev/sda
>
> /dev/sda:
> Timing cached reads: 8608 MB in 2.00 seconds = 4313.28 MB/sec
> Timing buffered disk reads: 202 MB in 3.02 seconds = 66.79 MB/sec
> [root at localhost ~]# hdparm -tTacdiIMpQ /dev/sda
>
> /dev/sda:
> IO_support = 0 (default 16-bit)
> readahead = 256 (on)
>
> Model=ST3250620NS , FwRev=3.AEG , SerialNo= 9QE2230L
> Config={ HardSect NotMFM HdSw>15uSec Fixed DTR>10Mbs RotSpdTol>.5% }
> RawCHS=16383/16/63, TrkSize=0, SectSize=0, ECCbytes=4
> BuffType=unknown, BuffSize=16384kB, MaxMultSect=16, MultSect=?16?
> CurCHS=16383/16/63, CurSects=16514064, LBA=yes, LBAsects=268435455
> IORDY=on/off, tPIO={min:240,w/IORDY:120}, tDMA={min:120,rec:120}
> PIO modes: pio0 pio1 pio2 pio3 pio4
> DMA modes: mdma0 mdma1 mdma2
> UDMA modes: udma0 udma1 udma2 udma3 udma4 udma5
> AdvancedPM=yes: unknown setting WriteCache=enabled
> Drive conforms to: Unspecified: ATA/ATAPI-1 ATA/ATAPI-2 ATA/ATAPI-3 ATA/ATAPI-4 ATA/ATAPI-5 ATA/ATAPI-6 ATA/ATAPI-7
>
> * signifies the current active mode
>
>
> ATA device, with non-removable media
> Model Number: ST3250620NS
> Serial Number: 9QE2230L
> Firmware Revision: 3.AEG
> Standards:
> Supported: 7 6 5 4
> Likely used: 7
> 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: 488397168
> device size with M = 1024*1024: 238475 MBytes
> device size with M = 1000*1000: 250059 MBytes (250 GB)
> Capabilities:
> LBA, IORDY(can be disabled)
> Queue depth: 32
> Standby timer values: spec'd by Standard, no device specific minimum
> R/W multiple sector transfer: Max = 16 Current = 16
> Advanced power management level: unknown setting (0xfefe)
> Recommended acoustic management value: 254, current value: 0
> 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=240ns 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
> * DOWNLOAD_MICROCODE
> * Advanced Power Management feature set
> SET_MAX security extension
> * 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
> 64-bit World wide name
> unknown 84[11]
> unknown 84[12]
> * SATA-I signaling speed (1.5Gb/s)
> * SATA-II signaling speed (3.0Gb/s)
> * Native Command Queueing (NCQ)
> * Phy event counters
> Device-initiated interface power management
> * Software settings preservation
> * SMART Command Transport (SCT) feature set
> * SCT LBA Segment Access (AC2)
> * SCT Error Recovery Control (AC3)
> * SCT Features Control (AC4)
> * SCT Data Tables (AC5)
> Security:
> Master password revision code = 65534
> supported
> not enabled
> not locked
> frozen
> not expired: security count
> not supported: enhanced erase
> Checksum: correct
> HDIO_GET_ACOUSTIC failed: Inappropriate ioctl for device
> Timing cached reads: 4502 MB in 2.00 seconds = 2252.78 MB/sec
> Timing buffered disk reads: 38 MB in 3.08 seconds = 12.35 MB/sec
>
>
>
> Thanks
>
> Todd
>
Hard drives have 2 main metrics when it comes to speed: throughput and
seek time. Throughput is the speed of reading/writing a large contiguous
file. Seek time is the delay while your hd is "seeking" for the next
piece of data (presumably in a different physical location on the drive).
3GB is a rating of the SATA bus, in essence how fast data *could* be
transferred from the drive, if the drive made that data available. Since
every drive nowadays has a cache built in (8-16mb usually), reading from
cache can probably go at 3GB (or speed of the cache, whichever is lower)
- but that's only the 8-16mb that has recently been accessed. If you
want to read a file your HD hasn't read recently, it has to seek, then
read it.
Here's where the paths differentiate: some users need high throughput,
and some need fast seek times. If you use the HD for storing a lot of
small files, e.g. Squid cache, then seek times are more important.
Otherwise (reading/writing large files) - throughput is more important.
There isn't really any way of improving the speed of a SATA drive - they
should run at top speed already. If you used IDE drive, there might've
been some settings to tweak for maximum throughput - but with SATA those
are moot (and no, IDE is not faster than SATA :)
Depending on how much more performance you need, you can check out:
* alternate filesystems. They're usually well-suited for a particular
way of operation (e.g. lots of small files) and are average on all other
tasks. Degree of improvement isn't very high - and highly depends on
usage patterns - feel lucky if you get 10%. The only cost here is time
to implement and maintain the system.
* high-end HDs, e.g. 10,000+ RPM. These can improve your performance
somewhat, in the range of 10-20% - but it stacks on top of performance
gain of alternate filesystems. This is probably the cheapest upgrade path.
* solid state HDs. These have no moving parts, and thus the seek times
should be 0 (or very close to it). Don't know about the throughput.. in
theory it should be higher than traditional HDs, but in practice...
dunno, go read reviews :) Since it's a new technology, these are still
pretty expensive. Oh, and I doubt the speedup will add up with alternate
filesystems.
* if you want to go all out, try getting a RAM drive. You insert
standard computer RAM into it and your computer sees it as an HD. Very
fast and very expensive (cost of RAM)
HTH
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