I don't know who told you this, but you are getting expected numbers. according to www.storage.ibm.com. an 18ES (18.3gig 7200RPM) has the folowing specs: susstained data rate of up to 20.2 MB/sec with a 7.0ms average seek time. http://www.storage.ibm.com/hardsoft/diskdrdl/ultra/18esdata.htm you have to remember, you are limited by media transfer rates, which allways lag behind bus transfer rates, which is why i tell people that even tho their UltraDMA/66 drive is fast, it's still no faster than what can be skimed off the platters, and a 40MB Ultrawide chain will still preform just as well. I did some benchmarks of the unloaded alpha 600, and if i remember right.. I was geting over 33MB/sec out of a 10k RPM disk Thank You, Ben Kochie (ben at nerp.net) *-----------------------* [ - * - * - * - * - * - * - * - ] | Unix/Linux Consulting | [ Haiku Error Message: ] | PC/Mac Repair | [ Chaos reigns within. ] | Networking | [ Reflect, repent, and reboot. ] | http://nerp.net | [ Order shall return. ] *-----------------------* [ - * - * - * - * - * - * - * - ] "Unix is user friendly, Its just picky about its friends." On Thu, 5 Oct 2000, Michael Josephson wrote: > On Thu, Oct 05, 2000 at 04:06:01PM -0500, Ben Kochie wrote: > > yep.. that's about normal.. you are hitting DISK preformance limits.. not > > chain limits.. here's what I get on a 10k RPM disk on an alpha 600 with a > > symbios card.. you are also hitting the PCI bus limit of 133MB. this is > > an active box.. so the numbers are a little low :( (load is about 2 right > > now) > > > > Timing buffered disk reads: 64 MB in 3.53 seconds = 18.13 MB/sec > > Timing buffer-cache reads: 128 MB in 3.06 seconds = 41.80 MB/sec > > > > that's for normal UltraWide > > > > this one is a K6-2 450, with a buslogic (mylex) scsi card, and a 7200 RPM > > disk (i think) (backup server, no load) > > > > Timing buffered disk reads: 64 MB in 5.54 seconds = 11.55 MB/sec > > Timing buffer-cache reads: 128 MB in 3.28 seconds = 39.02 MB/sec > > > > and finaly, a dual celeron with a 7200 RPM ide drive > > > > Timing buffered disk reads: 64 MB in 3.47 seconds = 18.44 MB/sec > > Timing buffer-cache reads: 128 MB in 1.49 seconds = 85.91 MB/sec > > > > all drives are fairly recent (less than 1 year old) IBM ultrastars, and > > IDE is a deskstar. > > > > On Thu, 5 Oct 2000, Michael Josephson wrote: > > > > > I'm running Debian (kernal 2.2.17) on a server at > > > home: PIII 700 256MB ram with an Adaptec 29160 SCSI > > > controller and an IBM ultra 160 hard drive. When I run > > > hdparm -Tt /dev/sda, it reports: > > > > > > Timing buffer-cache reads: ...= 128 MB/sec > > > Timing buffered disk reads: ...= 19.05 MB/sec > > > > > > I'm not expecting max performance, but 19 MB/sec is a > > > helluva lot slower than 160 MB/sec. Anyone have any > > > thoughts on this? > ---end quoted text--- > > I've got a new IBM ultrastar 7200rpm (purchased in June). The box currently > has no load. According to your numbers, I should be getting at least twice > the 19MB/sec. > > I'm not too worried about this. But I'm trying to understand as much as I can > about the hardware...I'm a programmer, not a doctor :-) I haven't noticed any > performance issues, but the results of hdparm indicates to me that things could > use some tuning. > > mj > -- > Michael Josephson > Software Development/Web Administration > mjj at mjjtech.net > www.mjjtech.net > > --------------------------------------------------------------------- > To unsubscribe, e-mail: tclug-list-unsubscribe at mn-linux.org > For additional commands, e-mail: tclug-list-help at mn-linux.org > --------------------------------------------------------------------- To unsubscribe, e-mail: tclug-list-unsubscribe at mn-linux.org For additional commands, e-mail: tclug-list-help at mn-linux.org