Hi Ram,
A friend of mines PC has recently started reading and writing dvds at x2.3
which is far to slow.
I have googled the prob and found that the prob is Dma mode has reverted
to
Pio mode as described here.
http://www.michna.com/kb/WxDMA.htm
I've got some good news and I have got some bad news for you.
First the bad I don't know why this happens, nor do I have a
permanent fix for you!
The good I do have a fix, that sets your Plextor to DMA mode in
less than 4 seconds, if you follow this instruction.
I had an Asus K7M board, I had The Plextor 12/10/32a as primary on the
secondarychannel, and a CD as slave on the secondary channel. On this
setup I couldn'trun both as DMA, the system would freeze during
operation, so the Plextor wasDMA and the CD was PIO. A few days ago I
upgraded to MSI K7T PRO2-a, and on this system both the Plextor and Cd
will run DMA simultanusly.
Unfortunately on both systems the Plextor would get reset to PIO on
it's own - usually after 'sleep' mode, some kind soul send me a
workaround.
You need to find this path in your registry:
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\{4D36E96A-E325-11CE-BFC1-08002BE10318}
In my present setup there is 7 keys under this path:
0000
0001
0002
0003
0004
0005
Properties
In my old setup the information I needed was in Key: 0002, but when
the workaround didn't work with my new MSI board, then I sought the
reason why, and found, that key 0002 and 0005 (presumably installed
with the new motherboard), had the same information, and that the new
motherboard takes it's information from key 0005. So if this doesn't
work on the default key 0002, look into one of the other keys, and see
if the information is there too, then maybe the system gets the
information from there - You will then have to change the line:
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\{4D36E96A-E325-11CE-BFC1-08002BE10318}\0002]
to the key with the information in, which on my system is:
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\{4D36E96A-E325-11CE-BFC1-08002BE10318}\0005]
The information is (you can copy it, and save as DMA_ON.reg if you
want to):
-------
Windows Registry Editor Version 5.00
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\{4D36E96A-E325-11CE-BFC1-08002BE10318}\0002]
"EnumPropPages32"="storprop.dll,IdePropPageProvider"
"InfPath"="mshdc.inf"
"InfSection"="atapi_Inst_secondary"
"ProviderName"="Microsoft"
"DriverDateData"=hex:00,40,99,31,33,2e,bf,01
"DriverDate"="11-14-1999"
"DriverVersion"="5.0.2183.1"
"MatchingDeviceId"="secondary_ide_channel"
"DriverDesc"="Secondary IDE Channel"
"MasterDeviceType"=dword:00000002
"SlaveDeviceType"=dword:00000002
"MasterDeviceTimingMode"=dword:00000410
"MasterDeviceTimingModeAllowed"=dword:ffffffff
"MasterIdDataCheckSum"=dword:000223db
"SlaveDeviceTimingMode"=dword:00000410
"SlaveDeviceTimingModeAllowed"=dword:ffffffff
"SlaveIdDataCheckSum"=dword:00009186
"UserMasterDeviceTimingModeAllowed"=dword:ffffffff
"UserSlaveDeviceTimingModeAllowed"=dword:ffffffff
------
The settings for:
"MasterDeviceTimingMode"
"MasterDeviceTimingModeAllowed"
"UserMasterDeviceTimingModeAllowed"
are different for UDMA, DMA and PIO mode.
If you set it like above you will get DMA on both channels, if your Cd
on the secondary channel can run UDMA, then change the key:
"SlaveDeviceTimingMode"=dword:00008010 which is UDMA.
You could also export the Key above, and just make the necessary
changes to
"MasterDeviceTimingMode"
"MasterDeviceTimingModeAllowed"
"UserMasterDeviceTimingModeAllowed"
and leave the slave at it's present settings, then save it as a REG
file.
Once you have done this, then run the REG file, it will ask you
whether you want add the information to the registry, when you answer
YES, you will get a onfirmation, that the information has been added
to the registry, and then the lextor is in DMA mode again .... until
next time it decides to go into PIO ode. I have a copy of DMA_ON.reg
on my desktop, and I use it if the Plextor is in PIO mode, the change
happens 'on the fly', no need to reboot.
Sorry I didn't have a permanent solution, hope this makes the pain
easier to live with, until someone comes with a BIOS upgrade, IDE
Driver or system patch, which permanently solves the problem.
I DO know that once Windows XP decides that the Plextor is only PIO
mode capable, then nothing 'normal' will pursuade it otherwise. But if
it's a fault on Windows side, or that the Plextor gives wrong
information to Windows about it self, or the IDE drivers reports the
wrong settings - I don't know.
I've noticed, that upgrades of the Plextor Bios and IDE drivers cause
a new scan of hardware, and the Plextor once again becomes DMA, but
once it's set to PIO with these drivers, then Windows remember this
setting and won't let you change it normally.
So even downgrading the BIOS won't reset it to DMA, if Windows once
has decided that with this BIOS it's only PIO capable, or with these
drivers it's only PIO capable, then 'it's forever'!!
Regards Leif
