Messages in this thread |  | | | Date | Sat, 15 Dec 2001 18:56:43 +0100 | | From | Rene Rebe <> | | Subject | Re: PDC20265 IDE controller trouble |
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Hi.
This is on a AMD K6-2 350Mhz, 128MB RAM, on a Ali Aladin5 based Gigabyte board 3x IBM DTLA 40GB discs on a Promisse TX2 Ultra 100 in a PCI slot.
Single transfer to one disk: server1:~ # hdparm -tT /dev/ide/host2/bus0/target0/lun0/disc
/dev/ide/host2/bus0/target0/lun0/disc: Timing buffer-cache reads: 128 MB in 2.12 seconds = 60.38 MB/sec Timing buffered disk reads: 64 MB in 2.86 seconds = 22.38 MB/sec
Dual transfer to disks on sperated channels (values per disk): server1:~ # hdparm -tT /dev/ide/host2/bus0/target0/lun0/disc
/dev/ide/host2/bus0/target0/lun0/disc: Timing buffer-cache reads: 128 MB in 4.13 seconds = 30.99 MB/sec Timing buffered disk reads: 64 MB in 4.66 seconds = 13.73 MB/sec
Dual transfer to disks on the same channel (values per dics): server1:~ # hdparm -tT /dev/ide/host2/bus0/target1/lun0/disc
/dev/ide/host2/bus0/target1/lun0/disc: Timing buffer-cache reads: 128 MB in 4.44 seconds = 28.83 MB/sec Timing buffered disk reads: 64 MB in 8.36 seconds = 7.66 MB/sec
Hey! This might be the cause for the slowdown I reported in another Raid5 / ReiserFS thread!!
Is this an general IDE issue or is some queueing code in the kernel rather bad/slow for this task???
On Sat, 15 Dec 2001 18:35:29 +0100 (MET) Jurij Smakov <jurij.smakov@telia.com> wrote:
> Hi! > > Recently I've got an Asus TUSL2 motherboard, which has an extra Promise > IDE RAID controller with a PDC20265 chip. I've connected two IBM 60 GB > disks to it (one disk per channel). I am using kernel 2.4.17-pre8 > (with CONFIG_BLK_DEV_PDC202XX=y and with/without CONFIG_PDC202XX_BURST=y), > which nicely detects the extra controller and both disks, hde and hdg. If > I test the writing and reading speed (hdparm -t, dd if=/dev/zero of=test > ...) separately for each disk, I get the expected figures, like 36-37 > MB/sec for reading, about 30 MB/sec for writing. If, however, I try to > write simultaneously to both disks, the performance drops drastically. The > rate for writing is then something like 3.5 MB/sec (!). I wonder if anyone > have seen anything like that or might have any ideas on how to solve the > problem. > > Suspecting the hardware, I've posted this message to > comp.os.linux.hardware first, but no one have seen such a behaviour. I > have also tried different sets of IDE cables. > > Best regards and TIA, > > > Jurij. > > P.S. Please cc responses to me, because I'm not on the list. > > - > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ >
k33p h4ck1n6 René
-- René Rebe (Registered Linux user: #248718 <http://counter.li.org>)
eMail: rene.rebe@gmx.net rene@rocklinux.org
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