Messages in this thread | | | From | "Brian Macy" <> | Subject | Absolutely horrid IDE performance... | Date | Tue, 24 Nov 1998 15:45:18 -0800 |
| |
I just installed an IBM Deskstar 10.1gig UDMA 7200rpm drive in one of my Linux boxes (kernel 2.0.35, a SuperMicro P6SBA board with a Celeron 266, 4 x 100MHz). The IDE drive is currently the only IDE device and is not in use (I'm running a Mylex BT-something or other and a SCSI Wide drive).
On /dev/hda: hdparm gives 6.68meg/sec time dd if=/dev/hda of=/dev/null bs=4096 count=16384 gives well under 1meg/sec (the more transfered the slower)
On /dev/sda (a junker Seagate WSCSI on the Mylex controller: hdparm varies greatly between 2.5meg/sec and 4.5meg/sec time dd... gives 4.6meg/sec
Can anyone explain the discrepancy? I can't see why there would be such a huge difference. From what I've experienced with 95/NT machines, the IBM UDMA drives are very fast. Linux even shows the system time required to be reasonable between SCSI/IDE... it just seems like the drive is just running slow (I thought it might be CPU overhead).
Thanks. Brian Macy
/var/log/dmesg ide: i82371 PIIX (Triton) on PCI bus 0 function 57 ide0: BM-DMA at 0xffa0-0xffa7 hda: IBM-DTTA-371010, 9641MB w/465kB Cache, CHS=1024/255/63, UDMA
#hdparm -I /dev/hda /dev/hda:
Model=BI-MTDAT3-1710 0 , FwRev=7TO77AB0, SerialNo= Config={ HardSect NotMFM HdSw>15uSec Fixed DTR>10Mbs } RawCHS=16383/16/63, TrkSize=0, SectSize=0, ECCbytes=34 BuffType=3(DualPortCache), BuffSize=465kB, MaxMultSect=16, MultSect=off DblWordIO=no, maxPIO=2(fast), DMA=yes, maxDMA=2(fast) CurCHS=16383/16/63, CurSects=16514064, LBA=yes, LBAsects=19746720 tDMA={min:120,rec:120}, DMA modes: sword0 sword1 sword2 mword0 mword1 mword2 IORDY=on/off, tPIO={min:240,w/IORDY:120}, PIO modes: mode3 mode4
#time dd if=/dev/hda of=/dev/null bs=4096 count=16384 0.01user 0.38system 2:13.61elapsed 0%CPU (0avgtext+0avgdata 0maxresident)k 0inputs+0outputs (85major+11minor)pagefaults 0swaps #time dd if=/dev/sda of=/dev/null bs=4096 count=16384 0.00user 0.20system 0:13.79elapsed 1%CPU (0avgtext+0avgdata 0maxresident)k 0inputs+0outputs (81major+11minor)pagefaults 0swaps
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.rutgers.edu Please read the FAQ at http://www.tux.org/lkml/
| |