Re: VIA MVP3 gives bad IDE UDMA33 performace ?!

From: Harald Koenig (koenig@tat.physik.uni-tuebingen.de)
Date: Fri Mar 24 2000 - 09:01:20 EST


On Mar 24, Harald Koenig wrote:

> Hi,
>
> is there any chance to get better IDE performace for VIA MVP3 chipset ?

update with some more data & new questions. `lspci -s7.1 -xxxvv' shows

00:07.1 IDE interface: VIA Technologies, Inc. VT82C586 IDE [Apollo] (rev 06) (prog-if 8a [Master SecP PriP])
        Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B-
        Status: Cap- 66Mhz- UDF- FastB2B+ ParErr- DEVSEL=medium >TAbort- <TAbort- <MAbort- >SERR- <PERR-
        Latency: 64 set
        Region 4: I/O ports at d000 [size=16]
00: 06 11 71 05 07 00 80 02 06 8a 01 01 00 40 00 00
10: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
20: 01 d0 00 00 00 00 00 00 00 00 00 00 00 00 00 00
30: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
40: 0a e2 09 16 68 13 e0 00 a8 a8 a8 21 ff 00 ff ff
50: 03 03 03 e2 00 00 00 00 a8 a8 a8 a8 00 00 00 00
60: 00 02 00 00 00 00 00 00 00 02 00 00 00 00 00 00
70: 02 00 00 00 00 00 00 00 82 00 00 00 00 00 00 00
80: 00 20 2f 01 00 00 00 00 00 00 00 00 00 00 00 00
90: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
a0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
b0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
c0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
d0: 06 00 71 05 00 00 00 00 00 00 00 00 00 00 00 00
e0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
f0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

and I wonder why offset 0x53 is set to 0xe2.

according to the PDF data sheet bit 0x20 set seems to indicae `UDMA33 PIO mode'
instead of `UDMA33 DMA mode' which seems to be what I'd like to use ?!
how can I clear this bit ? it's specified to be `read-only', so how do I
disable PIO and enable DMA ? or is this the wrong way to go ???

lower nibble of 0x53 seems to force `cycle time' to 4T while your setup example
in ide/via82cxxx.c seems to suggest that this should be 2T (0x0).

I'm using plain standard 33 MHz PCI, so I'd guess that 2T should be correct ?!

I tried to change register 0x53 to 0xe1 and 0xe0 and 0x62..0x60, but this
didn't make any difference :-(

thanks for hint...

>
> I'm using a 40GB 7200rpm Maxtor disk which can deliver ~28 MB/sec,
> but with my main board (DFI K6BV3+) I only get ~13-16 MB/sec :-(
>
> here is some information from kernel 2.3.51 startup and hdparm:
>
> Uniform Multi-Platform E-IDE driver Revision: 6.30
> VP_IDE: IDE controller on PCI bus 00 dev 39
> VP_IDE: not 100% native mode: will probe irqs later
> VT 82C598 Apollo MVP3 Chipset Core ATA-33
> Split FIFO Configuration: 16 Primary buffers, threshold = 3/4
> 0 Second. buffers, threshold = 1/2
> ide0: BM-DMA at 0xd000-0xd007, BIOS settings: hda:DMA, hdb:DMA
> ide0: VIA Bus-Master (U)DMA Timing Config Success
> hda: Maxtor 54098U8, ATA DISK drive
> ide0 at 0x1f0-0x1f7,0x3f6 on irq 14
> hda: Maxtor 54098U8, 39082MB w/2048kB Cache, CHS=79406/16/63, (U)DMA
> Partition check:
> hda: [EZD] [remap 0->1] [4982/255/63] hda1
>
>
> # hdparm -I /dev/hda
>
> /dev/hda:
>
> Model=aMtxro5 04898U , FwRev=AD26C00Q, SerialNo=8K30NECK
> Config={ Fixed }
> RawCHS=16383/16/63, TrkSize=0, SectSize=0, ECCbytes=57
> BuffType=3(DualPortCache), BuffSize=2048kB, MaxMultSect=16, MultSect=off
> DblWordIO=no, OldPIO=2, DMA=yes, OldDMA=0
> CurCHS=16383/16/63, CurSects=16514064, LBA=yes, LBAsects=80041248
> tDMA={min:120,rec:120}, DMA modes: mword0 mword1 mword2
> IORDY=on/off, tPIO={min:120,w/IORDY:120}, PIO modes: mode3 mode4
> UDMA modes: mode0 mode1 *mode2 mode3 mode4
>
>
>
> I've tried 'hdparm -m8 /dev/hda' and similar to change `MultSect=off'
> but this doesn't make any difference.
>
> I'll attach a small PS file which shows transfer rates for the whole 40GB
> (position in MB vs. MB/sec) with both UDMA33 (my board) and UDMA66
> (K7 system from a friend).
>
> as you can see, my UDMA33 system gives exactly half the performace
> for the outermost cylinders and surprisingly I get the same transfer
> as UDMA66 only for the very innermost cylinders! there both PCs
> give ~16.5 MB/sec.
>
>
> any idea/hint/suggestion what I can try to get better transfer rate
> with my main board ?
>
>
> btw: transfer rate is the same for clean 2.2.14 and 2.3.47/2.3.51 kernels.
>
>
> thanks for any hint,
>
> Harald
> --
> All SCSI disks will from now on ___ _____
> be required to send an email notice 0--,| /OOOOOOO\
> 24 hours prior to complete hardware failure! <_/ / /OOOOOOOOOOO\
> \ \/OOOOOOOOOOOOOOO\
> \ OOOOOOOOOOOOOOOOO|//
> Harald Koenig, \/\/\/\/\/\/\/\/\/
> Inst.f.Theoret.Astrophysik // / \\ \
> koenig@tat.physik.uni-tuebingen.de ^^^^^ ^^^^^

Harald

-- 
All SCSI disks will from now on                     ___       _____
be required to send an email notice                0--,|    /OOOOOOO\
24 hours prior to complete hardware failure!      <_/  /  /OOOOOOOOOOO\
                                                    \  \/OOOOOOOOOOOOOOO\
                                                      \ OOOOOOOOOOOOOOOOO|//
Harald Koenig,                                         \/\/\/\/\/\/\/\/\/
Inst.f.Theoret.Astrophysik                              //  /     \\  \
koenig@tat.physik.uni-tuebingen.de                     ^^^^^       ^^^^^

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