no merit from using DMA-66?
Hi all,
Please cc me. I am not subscribing to this list. Thanks :-)
I bought a new harddisk that can do DMA-66 lately(Matrox DiamodMax
17GB). However it doesn't look like I get any merit out of it at
all. I patch the kernel and everything seems to work fine. But hdparm
-t result is a bit slower than a DMA-33 harddisk I was using(around
18MB/sec). I heard somewhere that one should get around 25MB/sec from
DMA-66. Any idea? I am using potato, BE6 motherboard(HPT366 is DMA-66
ide controller for ide2 and ide3).
Here is what I did:
1) patch the kernel(2.2.14) with the infamouse hedrick patch. config:
CONFIG_BLK_DEV_IDE=y
# CONFIG_BLK_DEV_HD_IDE is not set
CONFIG_BLK_DEV_IDEDISK=y
# CONFIG_IDEDISK_MULTI_MODE is not set
CONFIG_BLK_DEV_IDECD=y
# CONFIG_BLK_DEV_IDETAPE is not set
# CONFIG_BLK_DEV_IDEFLOPPY is not set
# CONFIG_BLK_DEV_IDESCSI is not set
CONFIG_BLK_DEV_CMD640=y
# CONFIG_BLK_DEV_CMD640_ENHANCED is not set
CONFIG_BLK_DEV_RZ1000=y
CONFIG_BLK_DEV_IDEPCI=y
CONFIG_BLK_DEV_IDEDMA=y
CONFIG_IDEDMA_AUTO=y
# IDEDMA_NEW_DRIVE_LISTINGS is not set
IDEDMA_PCI_EXPERIMENTAL=y
# CONFIG_BLK_DEV_OFFBOARD is not set
CONFIG_BLK_DEV_HPT366=y
# HPT366_FAST_IRQ_PREDICTION is not set
# HPT366_MODE3 is not set
2) hook the new drive to ide2 so I now have /dev/hda(DMA-33),
/dev/hde(DMA-66). I have linux root filesystem on /dev/hda2(guess
what I have on /dev/hda1) and /usr and /home on /dev/hde1 and
/dev/hde2.
3) reboot with the new kernel. The boot message follow:
PIIX4: IDE controller on PCI bus 00 dev 39
PIIX4: not 100% native mode: will probe irqs later
ide0: BM-DMA at 0xf000-0xf007, BIOS settings: hda:DMA, hdb:pio
ide1: BM-DMA at 0xf008-0xf00f, BIOS settings: hdc:pio, hdd:pio
HPT366: onboard version of chipset, pin1=1 pin2=2
HPT366: IDE controller on PCI bus 00 dev 98
HPT366: not 100% native mode: will probe irqs later
ide2: BM-DMA at 0xb800-0xb807, BIOS settings: hde:DMA, hdf:pio
HPT366: IDE controller on PCI bus 00 dev 99
HPT366: not 100% native mode: will probe irqs later
ide3: BM-DMA at 0xc400-0xc407, BIOS settings: hdg:pio, hdh:pio
hda: QUANTUM FIREBALL CX6.4A, ATA DISK drive
hdc: ASUS CD-S400/A, ATAPI CDROM drive
hde: Maxtor 91700U5, ATA DISK drive
ide0 at 0x1f0-0x1f7,0x3f6 on irq 14
ide1 at 0x170-0x177,0x376 on irq 15
ide2 at 0xb000-0xb007,0xb402 on irq 11
hda: QUANTUM FIREBALL CX6.4A, 6149MB w/418kB Cache, CHS=784/255/63, UDMA(33)
hde: Maxtor 91700U5, 16228MB w/2048kB Cache, CHS=32972/16/63, UDMA(66)
hdc: ATAPI 40X CD-ROM drive, 128kB Cache
4) do hdparm -t with /dev/hda and /dev/hde I got:
Zero:/root# hdparm -t /dev/hda <---DMA-33
/dev/hda:
Timing buffered disk reads: 64 MB in 4.04 seconds = 15.84 MB/sec
Zero:/root# hdparm -t /dev/hde <---DMA-66
/dev/hde:
Timing buffered disk reads: 64 MB in 9.10 seconds = 7.03 MB/sec
I did this several times and got the same result. WTF it was slower
than DMA-33!!
5) I moved root file system to /dev/hde so all linux is in the same
drive now. rebooted and did hdparm test again. Now I got 18MB/sec
for both /dev/hda and /dev/hde.
6) I get another DMA-66 harddisk(Quantum 8GB) from a friend and hook
it too ide3. Now they all gave 18MB/sec from hdparm test.
7) HD benchamrk on Win98 tell me that the data transfer rate of
/dev/hdg is double of /dev/hda(Win can't see /dev/hde coz it has no
vfat partition), which it should be, had it work correctly.
So, I guess it is a problem of linux and my configuration. Can someone
help me get this right? Oh, here is harddisk config I got from
hdparm(both drives have same result)
multcount = 0 (off)
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)
I did fiddle with multcount, I/O support and unmaskirq but they seem
to help nothing.
Best Regards,
Vachi
-----
Vachirasuk Setalaphruk
ISE, Osaka University
Reply to: