Hello!
Please CC: me on replies,
Problem: ata disk on secondary controller of PDC20265
gives sub-par performance.
both disks have c3 and d1 set along with X69.
hdparm -tT /dev/hdg:
/dev/hdg:
Timing buffer-cache reads: 128 MB in 0.77 seconds =166.23 MB/sec
Timing buffered disk reads: 64 MB in 3.81 seconds = 16.80 MB/sec
compared to
hdparm -tT /dev/hde:
/dev/hde:
Timing buffer-cache reads: 128 MB in 0.73 seconds =175.34 MB/sec
Timing buffered disk reads: 64 MB in 1.82 seconds = 35.16 MB/sec
Setup:
kernel: 2.4.17
pdc20265 controller on asus a7v motherboard.
kernel config options:
CONFIG_BLK_DEV_PDC202XX=y
CONFIG_PDC202XX_BURST=y
# CONFIG_PDC202XX_FORCE is not set
# CONFIG_BLK_DEV_ATARAID_PDC is not set
similar behavior with redhat 7.2 updated kernel 2.4.9-21
hde: IBM-DTLA-307015, ATA DISK drive
hdg: MAXTOR 6L040J2, ATA DISK drive
Interesting stuff from dmesg:
ide2: BM-DMA at 0x8000-0x8007, BIOS settings: hde:DMA, hdf:pio
ide3: BM-DMA at 0x8008-0x800f, BIOS settings: hdg:DMA, hdh:pio
cat /proc/ide/ide2/config
pci bus 00 device 88 vid 105a did 0d30 channel 0
5a 10 30 0d 07 00 10 02 02 00 80 01 00 20 00 00
01 94 00 00 01 90 00 00 01 88 00 00 01 84 00 00
01 80 00 00 00 00 00 d4 00 00 00 00 5a 10 33 4d
00 00 00 00 58 00 00 00 00 00 00 00 0a 01 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
be 33 00 00 00 00 00 00 01 00 01 00 00 00 00 00
f1 24 41 00 c4 f3 4f 00 f1 24 41 00 c4 f3 4f 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
cat /proc/ide/ide3/config
pci bus 00 device 88 vid 105a did 0d30 channel 1
5a 10 30 0d 07 00 10 02 02 00 80 01 00 20 00 00
01 94 00 00 01 90 00 00 01 88 00 00 01 84 00 00
01 80 00 00 00 00 00 d4 00 00 00 00 5a 10 33 4d
00 00 00 00 58 00 00 00 00 00 00 00 0a 01 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
be 33 00 00 00 00 00 00 01 00 01 00 00 00 00 00
f1 24 41 00 c4 f3 4f 00 f1 24 41 00 c4 f3 4f 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
hdparm -i
/dev/hde
Model=IBM-DTLA-307015, FwRev=TX2OA50C, SerialNo=YF0YFFX4393
Config={ HardSect NotMFM HdSw>15uSec Fixed DTR>10Mbs }
RawCHS=16383/16/63, TrkSize=0, SectSize=0, ECCbytes=40
BuffType=DualPortCache, BuffSize=1916kB, MaxMultSect=16, MultSect=16
CurCHS=16383/16/63, CurSects=-66060037, LBA=yes, LBAsects=30003120
IORDY=on/off, tPIO={min:240,w/IORDY:120}, tDMA={min:120,rec:120}
PIO modes: pio0 pio1 pio2 pio3 pio4
DMA modes: mdma0 mdma1 mdma2 udma0 udma1 udma2 udma3 udma4 *udma5
AdvancedPM=yes: disabled (255)
Drive Supports : ATA/ATAPI-5 T13 1321D revision 1 : ATA-2 ATA-3 ATA-4
ATA-5
/dev/hdg
Model=MAXTOR 6L040J2, FwRev=A93.0300, SerialNo=662125114610
Config={ HardSect NotMFM HdSw>15uSec Fixed DTR>10Mbs }
RawCHS=16383/16/63, TrkSize=32256, SectSize=21298, ECCbytes=4
BuffType=DualPortCache, BuffSize=1820kB, MaxMultSect=16, MultSect=16
CurCHS=16383/16/63, CurSects=-66060037, LBA=yes, LBAsects=78177792
IORDY=on/off, tPIO={min:120,w/IORDY:120}, tDMA={min:120,rec:120}
PIO modes: pio0 pio1 pio2 pio3 pio4
DMA modes: mdma0 mdma1 mdma2 udma0 udma1 udma2 udma3 udma4 *udma5 udma6
AdvancedPM=no
Drive Supports : ATA/ATAPI-5 T13 1321D revision 1 : ATA-1 ATA-2 ATA-3
ATA-4 ATA-5
cat /proc/ide/pdc202xx
PDC20265 Chipset.
------------------------------- General Status
---------------------------------Burst Mode :
enabled
Host Mode : Normal
Bus Clocking : 33 PCI Internal
IO pad select : 10 mA
Status Polling Period : 8
Interrupt Check Status Polling Delay : 11
--------------- Primary Channel ---------------- Secondary Channel ----
enabled enabled
66 Clocking enabled enabled
Mode PCI Mode PCI
FIFO Empty FIFO Empty
--------------- drive0 --------- drive1 -------- drive0 ----------
drive1 -DMA enabled: yes no
yes no
DMA Mode: UDMA 4 NOTSET UDMA 4
NOTSET
PIO Mode: PIO 4 NOTSET PIO 4
NOTSET
What is going on? I do have ata100 cables.
Thanks,
-bharath
Hi,
I would expect the disk which acts slower(maxtor) to be atleast as fast
as the other one (ibm).
reasons:
1. Both are 7200RPM
2. The slower one(maxtor hdg) is one of the newer ata133 disks while
that faster one is ata100(ibm hde). I would expect atleast equal
performance from both.
Thanks,
-bharath
On Thu, 2002-02-28 at 14:55, Joseph Malicki wrote:
> Have you considered that perhaps one of your drives is just faster than the
> other?
> This happens.
>
> -joe
>
> ----- Original Message -----
> From: "Bharath Krishnan" <[email protected]>
> To: <[email protected]>
> Sent: Thursday, February 28, 2002 11:34 AM
> Subject: Yet another disk transfer speed problem
>
>
> > Hello!
> >
> > Please CC: me on replies,
> >
> > Problem: ata disk on secondary controller of PDC20265
> > gives sub-par performance.
> >
> > both disks have c3 and d1 set along with X69.
> >
> > hdparm -tT /dev/hdg:
> > /dev/hdg:
> > Timing buffer-cache reads: 128 MB in 0.77 seconds =166.23 MB/sec
> > Timing buffered disk reads: 64 MB in 3.81 seconds = 16.80 MB/sec
> >
> > compared to
> > hdparm -tT /dev/hde:
> > /dev/hde:
> > Timing buffer-cache reads: 128 MB in 0.73 seconds =175.34 MB/sec
> > Timing buffered disk reads: 64 MB in 1.82 seconds = 35.16 MB/sec
> >
> >
> > Setup:
> > kernel: 2.4.17
> > pdc20265 controller on asus a7v motherboard.
> > kernel config options:
> > CONFIG_BLK_DEV_PDC202XX=y
> > CONFIG_PDC202XX_BURST=y
> > # CONFIG_PDC202XX_FORCE is not set
> > # CONFIG_BLK_DEV_ATARAID_PDC is not set
> >
> > similar behavior with redhat 7.2 updated kernel 2.4.9-21
> >
> > hde: IBM-DTLA-307015, ATA DISK drive
> > hdg: MAXTOR 6L040J2, ATA DISK drive
> >
> > Interesting stuff from dmesg:
> > ide2: BM-DMA at 0x8000-0x8007, BIOS settings: hde:DMA, hdf:pio
> > ide3: BM-DMA at 0x8008-0x800f, BIOS settings: hdg:DMA, hdh:pio
> >
> > cat /proc/ide/ide2/config
> > pci bus 00 device 88 vid 105a did 0d30 channel 0
> > 5a 10 30 0d 07 00 10 02 02 00 80 01 00 20 00 00
> > 01 94 00 00 01 90 00 00 01 88 00 00 01 84 00 00
> > 01 80 00 00 00 00 00 d4 00 00 00 00 5a 10 33 4d
> > 00 00 00 00 58 00 00 00 00 00 00 00 0a 01 00 00
> > 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> > be 33 00 00 00 00 00 00 01 00 01 00 00 00 00 00
> > f1 24 41 00 c4 f3 4f 00 f1 24 41 00 c4 f3 4f 00
> > 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> > 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> > 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> > 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> > 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> > 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> > 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> > 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> > 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> >
> > cat /proc/ide/ide3/config
> > pci bus 00 device 88 vid 105a did 0d30 channel 1
> > 5a 10 30 0d 07 00 10 02 02 00 80 01 00 20 00 00
> > 01 94 00 00 01 90 00 00 01 88 00 00 01 84 00 00
> > 01 80 00 00 00 00 00 d4 00 00 00 00 5a 10 33 4d
> > 00 00 00 00 58 00 00 00 00 00 00 00 0a 01 00 00
> > 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> > be 33 00 00 00 00 00 00 01 00 01 00 00 00 00 00
> > f1 24 41 00 c4 f3 4f 00 f1 24 41 00 c4 f3 4f 00
> > 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> > 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> > 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> > 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> > 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> > 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> > 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> > 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> > 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> >
> > hdparm -i
> > /dev/hde
> > Model=IBM-DTLA-307015, FwRev=TX2OA50C, SerialNo=YF0YFFX4393
> > Config={ HardSect NotMFM HdSw>15uSec Fixed DTR>10Mbs }
> > RawCHS=16383/16/63, TrkSize=0, SectSize=0, ECCbytes=40
> > BuffType=DualPortCache, BuffSize=1916kB, MaxMultSect=16, MultSect=16
> > CurCHS=16383/16/63, CurSects=-66060037, LBA=yes, LBAsects=30003120
> > IORDY=on/off, tPIO={min:240,w/IORDY:120}, tDMA={min:120,rec:120}
> > PIO modes: pio0 pio1 pio2 pio3 pio4
> > DMA modes: mdma0 mdma1 mdma2 udma0 udma1 udma2 udma3 udma4 *udma5
> > AdvancedPM=yes: disabled (255)
> > Drive Supports : ATA/ATAPI-5 T13 1321D revision 1 : ATA-2 ATA-3 ATA-4
> > ATA-5
> >
> > /dev/hdg
> > Model=MAXTOR 6L040J2, FwRev=A93.0300, SerialNo=662125114610
> > Config={ HardSect NotMFM HdSw>15uSec Fixed DTR>10Mbs }
> > RawCHS=16383/16/63, TrkSize=32256, SectSize=21298, ECCbytes=4
> > BuffType=DualPortCache, BuffSize=1820kB, MaxMultSect=16, MultSect=16
> > CurCHS=16383/16/63, CurSects=-66060037, LBA=yes, LBAsects=78177792
> > IORDY=on/off, tPIO={min:120,w/IORDY:120}, tDMA={min:120,rec:120}
> > PIO modes: pio0 pio1 pio2 pio3 pio4
> > DMA modes: mdma0 mdma1 mdma2 udma0 udma1 udma2 udma3 udma4 *udma5 udma6
> > AdvancedPM=no
> > Drive Supports : ATA/ATAPI-5 T13 1321D revision 1 : ATA-1 ATA-2 ATA-3
> > ATA-4 ATA-5
> >
> > cat /proc/ide/pdc202xx
> > PDC20265 Chipset.
> > ------------------------------- General Status
> > ---------------------------------Burst Mode :
> > enabled
> > Host Mode : Normal
> > Bus Clocking : 33 PCI Internal
> > IO pad select : 10 mA
> > Status Polling Period : 8
> > Interrupt Check Status Polling Delay : 11
> > --------------- Primary Channel ---------------- Secondary Channel ----
> > enabled enabled
> > 66 Clocking enabled enabled
> > Mode PCI Mode PCI
> > FIFO Empty FIFO Empty
> > --------------- drive0 --------- drive1 -------- drive0 ----------
> > drive1 -DMA enabled: yes no
> > yes no
> > DMA Mode: UDMA 4 NOTSET UDMA 4
> > NOTSET
> > PIO Mode: PIO 4 NOTSET PIO 4
> > NOTSET
> >
> >
> > What is going on? I do have ata100 cables.
> >
> > Thanks,
> >
> > -bharath
> > -
> > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> > the body of a message to [email protected]
> > More majordomo info at http://vger.kernel.org/majordomo-info.html
> > Please read the FAQ at http://www.tux.org/lkml/
> >
>
Have you considered that perhaps one of your drives is just faster than the
other?
This happens.
-joe
----- Original Message -----
From: "Bharath Krishnan" <[email protected]>
To: <[email protected]>
Sent: Thursday, February 28, 2002 11:34 AM
Subject: Yet another disk transfer speed problem
> Hello!
>
> Please CC: me on replies,
>
> Problem: ata disk on secondary controller of PDC20265
> gives sub-par performance.
>
> both disks have c3 and d1 set along with X69.
>
> hdparm -tT /dev/hdg:
> /dev/hdg:
> Timing buffer-cache reads: 128 MB in 0.77 seconds =166.23 MB/sec
> Timing buffered disk reads: 64 MB in 3.81 seconds = 16.80 MB/sec
>
> compared to
> hdparm -tT /dev/hde:
> /dev/hde:
> Timing buffer-cache reads: 128 MB in 0.73 seconds =175.34 MB/sec
> Timing buffered disk reads: 64 MB in 1.82 seconds = 35.16 MB/sec
>
>
> Setup:
> kernel: 2.4.17
> pdc20265 controller on asus a7v motherboard.
> kernel config options:
> CONFIG_BLK_DEV_PDC202XX=y
> CONFIG_PDC202XX_BURST=y
> # CONFIG_PDC202XX_FORCE is not set
> # CONFIG_BLK_DEV_ATARAID_PDC is not set
>
> similar behavior with redhat 7.2 updated kernel 2.4.9-21
>
> hde: IBM-DTLA-307015, ATA DISK drive
> hdg: MAXTOR 6L040J2, ATA DISK drive
>
> Interesting stuff from dmesg:
> ide2: BM-DMA at 0x8000-0x8007, BIOS settings: hde:DMA, hdf:pio
> ide3: BM-DMA at 0x8008-0x800f, BIOS settings: hdg:DMA, hdh:pio
>
> cat /proc/ide/ide2/config
> pci bus 00 device 88 vid 105a did 0d30 channel 0
> 5a 10 30 0d 07 00 10 02 02 00 80 01 00 20 00 00
> 01 94 00 00 01 90 00 00 01 88 00 00 01 84 00 00
> 01 80 00 00 00 00 00 d4 00 00 00 00 5a 10 33 4d
> 00 00 00 00 58 00 00 00 00 00 00 00 0a 01 00 00
> 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> be 33 00 00 00 00 00 00 01 00 01 00 00 00 00 00
> f1 24 41 00 c4 f3 4f 00 f1 24 41 00 c4 f3 4f 00
> 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>
> cat /proc/ide/ide3/config
> pci bus 00 device 88 vid 105a did 0d30 channel 1
> 5a 10 30 0d 07 00 10 02 02 00 80 01 00 20 00 00
> 01 94 00 00 01 90 00 00 01 88 00 00 01 84 00 00
> 01 80 00 00 00 00 00 d4 00 00 00 00 5a 10 33 4d
> 00 00 00 00 58 00 00 00 00 00 00 00 0a 01 00 00
> 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> be 33 00 00 00 00 00 00 01 00 01 00 00 00 00 00
> f1 24 41 00 c4 f3 4f 00 f1 24 41 00 c4 f3 4f 00
> 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>
> hdparm -i
> /dev/hde
> Model=IBM-DTLA-307015, FwRev=TX2OA50C, SerialNo=YF0YFFX4393
> Config={ HardSect NotMFM HdSw>15uSec Fixed DTR>10Mbs }
> RawCHS=16383/16/63, TrkSize=0, SectSize=0, ECCbytes=40
> BuffType=DualPortCache, BuffSize=1916kB, MaxMultSect=16, MultSect=16
> CurCHS=16383/16/63, CurSects=-66060037, LBA=yes, LBAsects=30003120
> IORDY=on/off, tPIO={min:240,w/IORDY:120}, tDMA={min:120,rec:120}
> PIO modes: pio0 pio1 pio2 pio3 pio4
> DMA modes: mdma0 mdma1 mdma2 udma0 udma1 udma2 udma3 udma4 *udma5
> AdvancedPM=yes: disabled (255)
> Drive Supports : ATA/ATAPI-5 T13 1321D revision 1 : ATA-2 ATA-3 ATA-4
> ATA-5
>
> /dev/hdg
> Model=MAXTOR 6L040J2, FwRev=A93.0300, SerialNo=662125114610
> Config={ HardSect NotMFM HdSw>15uSec Fixed DTR>10Mbs }
> RawCHS=16383/16/63, TrkSize=32256, SectSize=21298, ECCbytes=4
> BuffType=DualPortCache, BuffSize=1820kB, MaxMultSect=16, MultSect=16
> CurCHS=16383/16/63, CurSects=-66060037, LBA=yes, LBAsects=78177792
> IORDY=on/off, tPIO={min:120,w/IORDY:120}, tDMA={min:120,rec:120}
> PIO modes: pio0 pio1 pio2 pio3 pio4
> DMA modes: mdma0 mdma1 mdma2 udma0 udma1 udma2 udma3 udma4 *udma5 udma6
> AdvancedPM=no
> Drive Supports : ATA/ATAPI-5 T13 1321D revision 1 : ATA-1 ATA-2 ATA-3
> ATA-4 ATA-5
>
> cat /proc/ide/pdc202xx
> PDC20265 Chipset.
> ------------------------------- General Status
> ---------------------------------Burst Mode :
> enabled
> Host Mode : Normal
> Bus Clocking : 33 PCI Internal
> IO pad select : 10 mA
> Status Polling Period : 8
> Interrupt Check Status Polling Delay : 11
> --------------- Primary Channel ---------------- Secondary Channel ----
> enabled enabled
> 66 Clocking enabled enabled
> Mode PCI Mode PCI
> FIFO Empty FIFO Empty
> --------------- drive0 --------- drive1 -------- drive0 ----------
> drive1 -DMA enabled: yes no
> yes no
> DMA Mode: UDMA 4 NOTSET UDMA 4
> NOTSET
> PIO Mode: PIO 4 NOTSET PIO 4
> NOTSET
>
>
> What is going on? I do have ata100 cables.
>
> Thanks,
>
> -bharath
> -
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to [email protected]
> More majordomo info at http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at http://www.tux.org/lkml/
>
Bharath Krishnan wrote:
>
> Hi,
>
> I would expect the disk which acts slower(maxtor) to be atleast as fast
> as the other one (ibm).
>
> reasons:
>
> 1. Both are 7200RPM
Not enough to get anywhere near equal performance.
This also depends on how densely data is packed onto a single track.
A 7200 RPM drive reads a whole track in 1/7200 minute, or 1/120 second.
That limits the maximum speed - but how much data is there
on a single track? Slow 7200 RPM drives have many tracks and little
data on each track. Fast drives have fewer tracks and more
data in each. Note that this has nothing to do with disk geometry
reported by hdparm, that geometry is just a lie.
All new drives have a varying amount of data per track as the
outermost tracks are longer than the innermost.
That of course also means the speed varies a lot depending on
_what_ track is used for testing.
My atlas IV scsi drive does 21MB/s on the outer tracks and 15MB/s
on the inner tracks according to specs. Running bonnie tests
on partitions at either end of the drive confirms the difference.
So, expect 7200 RPM drives from different manufacturers to
have very different transfer speeds. Or even different sized
drives from the same.
> 2. The slower one(maxtor hdg) is one of the newer ata133 disks while
> that faster one is ata100(ibm hde). I would expect atleast equal
> performance from both.
133 or 100 sets an upper limit of 133 or 100MB/s for sure, but that
doesn't matter _at all_ because the platters aren't that fast
anyway. The best you'll ever get depends on how much data they fit
on the outermost track. The 133 interface will be 33% faster when
transferring small amounts of data to or from the drive's internal
cache, but it won't impact transfers bigger than the cacee size
at all. hdparms 64M test is bigger than the drive's internal cache
which probably is a few megs only.
Helge Hafting
Bharath Krishnan proclaimed:
>
> Hi,
>
> I would expect the disk which acts slower(maxtor) to be atleast as fast
> as the other one (ibm).
Could you provide fdisk -l for both? For some odd reason unknown to me
some filesystems give slower results with hdparm than others, even with
the buffer-cache reads (which are intended to measure memory speed, not
drive speed, and thus should be the same for all drives on a given
mainboard). Also, hdparm directly on the drive device is often a bit
slower than hdparm for the first (outermost) partition. These problems
have been far worse in older kernels, though. With 2.2 I once
benchmarked a vfat-partition at half the speed the same partition gave
as ext2.
Holger
Hi,
I may have been overly simplistic/ignorant in my reasoning.
But, in this case, the slow disk is rated pretty high in performance. It
can supposedly do 40MB/sec. Maxtor sells it as D740X, their performance
range.
Thanks,
-bharath
On Fri, 1 Mar 2002, Helge Hafting wrote:
> Bharath Krishnan wrote:
> >
> > Hi,
> >
> > I would expect the disk which acts slower(maxtor) to be atleast as fast
> > as the other one (ibm).
> >
> > reasons:
> >
> > 1. Both are 7200RPM
> Not enough to get anywhere near equal performance.
> This also depends on how densely data is packed onto a single track.
> A 7200 RPM drive reads a whole track in 1/7200 minute, or 1/120 second.
> That limits the maximum speed - but how much data is there
> on a single track? Slow 7200 RPM drives have many tracks and little
> data on each track. Fast drives have fewer tracks and more
> data in each. Note that this has nothing to do with disk geometry
> reported by hdparm, that geometry is just a lie.
> All new drives have a varying amount of data per track as the
> outermost tracks are longer than the innermost.
> That of course also means the speed varies a lot depending on
> _what_ track is used for testing.
>
> My atlas IV scsi drive does 21MB/s on the outer tracks and 15MB/s
> on the inner tracks according to specs. Running bonnie tests
> on partitions at either end of the drive confirms the difference.
>
> So, expect 7200 RPM drives from different manufacturers to
> have very different transfer speeds. Or even different sized
> drives from the same.
>
> > 2. The slower one(maxtor hdg) is one of the newer ata133 disks while
> > that faster one is ata100(ibm hde). I would expect atleast equal
> > performance from both.
>
>
> 133 or 100 sets an upper limit of 133 or 100MB/s for sure, but that
> doesn't matter _at all_ because the platters aren't that fast
> anyway. The best you'll ever get depends on how much data they fit
> on the outermost track. The 133 interface will be 33% faster when
> transferring small amounts of data to or from the drive's internal
> cache, but it won't impact transfers bigger than the cacee size
> at all. hdparms 64M test is bigger than the drive's internal cache
> which probably is a few megs only.
>
> Helge Hafting
>
-bharath
Hi,
Here is fdisk -l results:
[root@yakuza root]# /sbin/fdisk -l /dev/hdg
Disk /dev/hdg: 255 heads, 63 sectors, 4866 cylinders
Units = cylinders of 16065 * 512 bytes
Device Boot Start End Blocks Id System
/dev/hdg1 * 1 255 2048256 6 FAT16
[root@yakuza root]# /sbin/fdisk -l /dev/hde
Disk /dev/hde: 255 heads, 63 sectors, 1867 cylinders
Units = cylinders of 16065 * 512 bytes
Device Boot Start End Blocks Id System
/dev/hde1 1 6 48163+ 83 Linux
/dev/hde2 7 1056 8434125 83 Linux
/dev/hde3 * 1154 1867 5735205 7 HPFS/NTFS
/dev/hde4 1057 1153 779152+ f Win95 Ext'd (LBA)
/dev/hde5 1057 1153 779121 82 Linux swap
Partition table entries are not in disk order
As you can see, I have a fat16 partition on hdg. I can delete it and make
an ext3 partition there and see if that changes anything.
Thanks,
-bharath
>>>
Could you provide fdisk -l for both? For some odd reason unknown to me
some filesystems give slower results with hdparm than others, even with
the buffer-cache reads (which are intended to measure memory speed, not
drive speed, and thus should be the same for all drives on a given
mainboard). Also, hdparm directly on the drive device is often a bit
slower than hdparm for the first (outermost) partition. These problems
have been far worse in older kernels, though. With 2.2 I once
benchmarked a vfat-partition at half the speed the same partition gave
as ext2.
Holger
-bharath