[Date Prev][Date Next]   [Thread Prev][Thread Next]   [Thread Index] [Date Index] [Author Index]

Re: Hard Drive data rates



On Friday 28 September 2007 03:00:11 pm Karl Larsen wrote:
> Dave Stevens wrote:
> > On Friday 28 September 2007 10:50:32 am Karl Larsen wrote:
> >>     I was lead to mis-understand the data rate of my new SATA hard
> >> drive. It indicated that the data rate was 3 GB/sec. But some checking
> >> with Google said the Hard Drive makers are very free with their units.
> >> To be specific a SATA drive is 3000 MegaBits/second. This boils down to
> >> about 375 MB.
> >>
> >>     The old standard IDE parallel 40 pin plug is rated for a rate of 112
> >> MB at the fastest to 78 GB at the slowest part of the platter. So in my
> >> case I will not see a huge change moving to my SATA hard drive. I will
> >> stay here on the new IDE much longer.
> >
> > I'd be very interested in seeing the command and output for that drive
> > using hdparm -iItT
> >
> >> --
> >>
> >> 	Karl F. Larsen, AKA K5DI
> >> 	Linux User
> >> 	#450462   http://counter.li.org.
> >
> > Karl,
> >
> > I use a Seagate 320 gig ES SATA drive. This is a 3 Gb/sec drive BUT - it
> > was shipped with a jumper installed limiting it to half that rate, and
> > this rate is in any case a very optimistic one. Using hdparm as suggested
> > consistently gives me 78 MB/sec. That seems to be as good as it gets.
> > Also this is a very artificial figure, I have an old (about ten years) 9
> > gig SCSI drive that does about half that. It seems that the recent
> > addition of NCQ to SATA drives makes more of an improvement in heavily
> > loaded scenarios but quantifying this is not simple or unambiguous. I
> > want to try reconfiguring this setup in raid 0 but won't be able to do so
> > for a while. I know that another recent Seagate drive, their 400G ATA
> > gives transfer rates using hdparm -tT of about 50 MB/sec.
>
> There appears to be something wrong with hdparm on my computer. It only
> does this with all the various -tT and such:
>
> [root k5di /]# hdparm -iItT
>
> hdparm - get/set hard disk parameters - version v6.9
>
> Usage:  hdparm  [options] [device] ..
>
> Options:
>  -a   get/set fs readahead
>  -A   set drive read-lookahead flag (0/1)
>  -b   get/set bus state (0 == off, 1 == on, 2 == tristate)
>  -B   set Advanced Power Management setting (1-255)
>  -c   get/set IDE 32-bit IO setting
>  -C   check IDE power mode status
>  -d   get/set using_dma flag
>  --direct  use O_DIRECT to bypass page cache for timings
>  -D   enable/disable drive defect management
>  -E   set cd-rom drive speed
>  -f   flush buffer cache for device on exit
>  -g   display drive geometry
>  -h   display terse usage information
>  -H   read temperature from drive (Hitachi only)
>  -i   display drive identification
>  -I   detailed/current information directly from drive
>  --Istdin  read identify data from stdin as ASCII hex
>  --Istdout write identify data to stdout as ASCII hex
>  -k   get/set keep_settings_over_reset flag (0/1)
>  -K   set drive keep_features_over_reset flag (0/1)
>  -L   set drive doorlock (0/1) (removable harddisks only)
>  -M   get/set acoustic management (0-254, 128: quiet, 254: fast)
> (EXPERIMENTAL)
>  -m   get/set multiple sector count
>  -n   get/set ignore-write-errors flag (0/1)
>  -p   set PIO mode on IDE interface chipset (0,1,2,3,4,...)
>  -P   set drive prefetch count
>  -q   change next setting quietly
>  -Q   get/set DMA tagged-queuing depth (if supported)
>  -r   get/set device  readonly flag (DANGEROUS to set)
>  -R   register an IDE interface (DANGEROUS)
>  -s   set power-up in standby flag (0/1)
>  -S   set standby (spindown) timeout
>  -t   perform device read timings
>  -T   perform cache read timings
>  -u   get/set unmaskirq flag (0/1)
>  -U   un-register an IDE interface (DANGEROUS)
>  -v   defaults; same as -mcudkrag for IDE drives
>  -V   display program version and exit immediately
>  -w   perform device reset (DANGEROUS)
>  -W   set drive write-caching flag (0/1) (DANGEROUS)
>  -x   tristate device for hotswap (0/1) (DANGEROUS)
>  -X   set IDE xfer mode (DANGEROUS)
>  -y   put IDE drive in standby mode
>  -Y   put IDE drive to sleep
>  -Z   disable Seagate auto-powersaving mode
>  -z   re-read partition table
>  --security-help  display help for ATA security commands
>
>     So I can't use this for some reason.
>

you have to tell it what drive to check, so #hdparm -iItT /dev/sda for 
example, if your SATA drive is the first one.

Dave

>
>
> --
>
> 	Karl F. Larsen, AKA K5DI
> 	Linux User
> 	#450462   http://counter.li.org.



[Date Prev][Date Next]   [Thread Prev][Thread Next]   [Thread Index] [Date Index] [Author Index]