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.
