Hello Carsten, Thank you for your reply. I will give some more information: All three discs are DMA-enabled, as the output from hdparm -v showed: using_dma = 1 (on). Also umasirq, multicount, -X66 and I/O support were set to obtain maximal rates. Although the setting of umaskirq and -X66 seem not to make any difference when it comes to peformance tests. I can't give you any detaild figures because at present my computer is at another place. The performance test (with hdparm -t), while no other major processes were present, showed good results for sustained data transfer, ranging from about 27Mb/s 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? Ed Vaessen -----Oorspronkelijk bericht----- Van: Carsten Becher [mailto:cb-maillist@gmx.de] Verzonden: dinsdag 13 augustus 2002 13:03 Aan: Vaessen E.M.J. (Ed) CC: suse-linux@suse.com Onderwerp: Re: HD performance dropping while copying Hoi !
I have a BX-133 RAID mother board containing the Highpoint's HTP370 ATA-100 RAID 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.
I have the impression that performance is especially worse when dealing with large files ( > 1 Gb).
There might be some problem with the HD-access mode . Possibly they are set to PIO-mode instead of DMA or U-DMA . In PIO-mode the cpu needs to do all the work , with DMA the device can write directly to memory without bothering the cpu . Check with hdparm -v /dev/hda . Possible output would be : /dev/hda: multcount = 16 (on) I/O support = 0 (default 16-bit) unmaskirq = 0 (off) using_dma = 1 (on) keepsettings = 0 (off) nowerr = 0 (off) readonly = 0 (off) readahead = 8 (on) geometry = 7476/255/63, sectors = 120103200, start = 0 This is an IBM 62 GB IDE drive . Performance for comparision is : /dev/hda: Timing buffered disk reads: 64 MB in 3.37 seconds = 18.99 MB/sec (Connected at DMA-66 interface) same type of drive at DMA-100 /dev/hde: Timing buffered disk reads: 64 MB in 1.69 seconds = 37.87 MB/sec cu Carsten -- Antworten und Fragen bitte als PM an carsten-becher@cbecher.de GMX - Die Kommunikationsplattform im Internet. http://www.gmx.net -- 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. ************************************************************************