Messages in this thread | | | Date | Mon, 19 Mar 2001 22:22:35 +0000 | From | quintaq@yahoo ... | Subject | Re: UDMA 100 / PIIX4 question |
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On Mon, 19 Mar 2001 12:17:38 -0800 Tim Moore <timothymoore@bigfoot.com> wrote:
> Jeremy Jackson wrote: > > > > Tim Moore wrote: > > > 15MB/s for hdparm is about right. > > > > Yes, since hdparm -t measures *SUSTAINED* transfers... the actual > "head rate" of data reads from > > disk surface. Only if you read *only* data that is alread in > harddrive's cache will you get a speed > > close to the UDMA mode of the drive/controller. The cache is around > 1Mbyte, so for a split-second > > re-read of some data.... > > Apologies for the too brief answer. Sustained real world transfer rates > for the PIIX4 under ideal > setup conditions and a quiet bus are 14-18MB/s. Faster disk > architecture and forcing ide driver > parameters will not change this. > > Here's what you might expect from this disk family with an ATA-66 > capable chipset: > > [tim@abit tim]# hdparm -i /dev/hda; hdparm -tT /dev/hda > <snip>
> /dev/hda: > Timing buffer-cache reads: 128 MB in 0.81 seconds =158.02 MB/sec > Timing buffered disk reads: 64 MB in 1.85 seconds = 34.59 MB/sec > > Larger sustained transfers are about 75% of the burst/cache influenced > hdparm timings. > > [tim@abit tim]# time dd if=/dev/hda of=/dev/null bs=1k count=500k > 512000+0 records in > 512000+0 records out > 0.340u 6.780s 0:19.68 36.1% 0+0k 0+0io 115pf+0w > [tim@abit tim]# echo "512000/19.68" | bc -q > 26016 >
Hi,
First, many thanks to you both for responding (and Jerry for his further post mentioned below). Can I throw in the some actual figures just obtained on my system, and ask if these are consistent with what you are saying ?
cat /proc/ide/piix :
Intel PIIX4 Ultra 100 Chipset. --------------- Primary Channel ---------------- Secondary Channel ------------- enabled enabled --------------- drive0 --------- drive1 -------- drive0 ---------- drive1 ------ DMA enabled: yes no yes no UDMA enabled: yes no yes no UDMA enabled: 5 X 2 X UDMA DMA PI
hdparm -tT /dev/hda :
/dev/hda: Timing buffer-cache reads: 128 MB in 1.04 seconds =123.08 MB/sec Timing buffered disk reads: 64 MB in 4.24 seconds = 15.09 MB/sec
time dd if=/dev/hda of=/dev/null bs=1k count=500k : 512000+0 records in 512000+0 records out
real 0m26.636s user 0m0.220s sys 0m8.190s
(d) bonnie -s 1000
---Sequential Output (nosync)--- ---Sequential Input-- --Rnd Seek- -Per Char- --Block--- -Rewrite-- -Per Char- --Block--- --04k (03)- Machine MB K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU /sec %CPU 1*1000 10532 91.3 17757 11.3 6481 5.2 9604 71.1 20937 12.1 131.7 1.9
I had just written the above when the following post from Jeremy arrived :
"You should be able to get about 30 MB/s at the start of the disk (zone 0) so if you were testing say /dev/hda1 which is at the start of the disk it should be faster.
Try hdparm -i /dev/hda (or whatever) .. . note the reported MaxMultSect= value, and put it in place of X in command:
hdparm -u 1 -d 1 -m X -c 1 /dev/hda
Cheers,
Jeremy
PS - please let me know if this fixed your problem, since I have a system with the same motherboard."
There is a Win partition - so I do not think I am at the start of the drive.
hdparm -i /dev/hda gives :
/dev/hda:
Model=IBM-DTLA-307030, FwRev=TX4OA50C, SerialNo=YKDYKLN6151 Config={ HardSect NotMFM HdSw>15uSec Fixed DTR>10Mbs } RawCHS=16383/16/63, TrkSize=0, SectSize=0, ECCbytes=40 BuffType=3(DualPortCache), BuffSize=1916kB, MaxMultSect=16, MultSect=16 DblWordIO=no, OldPIO=2, DMA=yes, OldDMA=2 CurCHS=16383/16/63, CurSects=16514064, LBA=yes, LBAsects=60036480 tDMA={min:120,rec:120}, DMA modes: mword0 mword1 mword2 IORDY=on/off, tPIO={min:240,w/IORDY:120}, PIO modes: mode3 mode4 UDMA modes: mode0 mode1 mode2 mode3 mode4 *mode5 Drive Supports : Reserved : ATA-2 ATA-3 ATA-4 ATA-5
I therefore tried hdparm -u 1 -d 1 -m 16 -c 1 -X69 /dev/hda :
/dev/hda: setting 32-bit I/O support flag to 1 setting multcount to 16 setting unmaskirq to 1 (on) setting using_dma to 1 (on) setting xfermode to 69 (UltraDMA mode5) multcount = 16 (on) I/O support = 1 (32-bit) unmaskirq = 1 (on) using_dma = 1 (on)
Then hdparm -tT /dev/hda
/dev/hda: Timing buffer-cache reads: 128 MB in 1.04 seconds =123.08 MB/sec Timing buffered disk reads: 64 MB in 4.08 seconds = 15.69 MB/sec
These are, I fear, the figures I usually see.
Bed-time for Brits.
Regards,
Geoff
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