Hello Philipp, I must have overseen that english list and will subscribe to it. As for your remarks with regard to two harddisks being attached to one cable: that is of course true. I forgot to mention that when copying a 1.5Gb file from /dev/hde to /dev/hdg it took about 3 minutes, so the transfer rate is about 8Mb/s between 2 HD's attached at different cables. That is still slow. The DMA is set for all 3 HD's, as /hdparm -v showed: using_dma = 1 (on) I also used "maximal" settings for multicount, I/O support, umaskirq and X (-X66). It seems the latter two are not important, as the performance test "hdparm -t" shows always the same and quite good data transfer rates: 27Mb/s and and 35Mb/s for the MAXTORS and 45Mb/s for the IBM. When reading the dmesg, that shows the disc modes all to be udma5, marked with an asterisk *. Everything seems right. The only thing I found was that the cables had all black connectors and somewhere I read that the so-called 80 pin cable might have different coloured cables? Greetings, Ed -----Oorspronkelijk bericht----- Van: Philipp Zacharias [mailto:philipp.zacharias@gmx.net] Verzonden: dinsdag 13 augustus 2002 13:06 Aan: suse-linux@suse.com Onderwerp: Re: HD performance dropping while copying Hi Ed, On Tuesday, 13. August 2002 10:49 Vaessen, E.M.J. (Ed) wrote: first of all, I'd suggest you subscribe to suse-linux-e@suse.com as that list is in English while in suse-linux@suse.com generally German language is used. [...]

From scratch I installed SuSE 8.0 on the system where 1 MAXTOR drive is connected to ide3 (/dev/hde), 1 MAXTOR to ide4 (/dev/hdg) and 1 IBM to ide4 (/dev/hdh). All are ATA/100 discs. All have at least a few Gb free space on each of them.

File copy performance to and from the IBM at /dev/hdh is awfully slow: it starts with a few Megabytes per second and quickly drops to something less than 1 Mb/s. Unusable if you want to copy a video production directory of 35 Gb.

If you copy from /dev/hdh to /dev/hdg this low performance should result in both harddisks being attached to the same controller. As IDE-controllers can handle only one disk at a time, the transfer rate is much lower than copying from one disk to another disk which is attached to another controller.

If I look at the processes with "top" then the CPU-usage of kdeinit (or cp, depending how you start the file copy) rises to more then 80%. The data transfer between /dev/hde and /dev/hdg is better, but here too I witness a drop in performance: starting with 15Mb/s and gradually settling to some 5 Mb/s. Haven't checked CPU-usage here.

Looks like you haven't enabled DMA (Direct Memory Access) for your Harddisk. What output do you get when running hdparm -d /dev/hdX (using e, g and h instead of X) as root? [...] bye Philipp -- registered Linux user number 258854 HOW-TO? -> GOTO http://counter.li.org/ -- Um die Liste abzubestellen, schicken Sie eine Mail an: suse-linux-unsubscribe@suse.com Um eine Liste aller verfügbaren Kommandos zu bekommen, schicken Sie eine Mail an: suse-linux-help@suse.com Disclaimer ************************************************************************ Aan dit bericht kunnen geen rechten worden ontleend. Dit bericht is uitsluitend bestemd voor de geadresseerde. Als u dit bericht per abuis hebt ontvangen, wordt u verzocht het te vernietigen en de afzender te informeren. Wij adviseren u om bij twijfel over de juistheid of de volledigheid van de mail contact met afzender op te nemen. ************************************************************************