DMA & two optical drives

[678]

Hi all:

I'm wondering: if I have two optical drives connected together, can I
get them both use DMA?

Right now I have one CD-RW connected to a DVD-ROM: CD-RW as master and
DVD-ROM as slave. Under "Properties" in "Device Manager" it says current
mode of transfer for device 0 is "Ultra DMA" and for device 1 it is
"PIO", although in the transfer mode boxes both have "DMA if available".
It looks like to me only one drive -- I am guess it is the CD-RW -- is
using DMA and the other one is not, and the reason being DMA is only
available for one of the drives. Am I correct?

If not, is there a way for both of them to use DMA?

If only one of them can use DMA, then which one would benefit more from
it: CD-RW or DVD-ROM?

My OS is XP Pro and I'm using P4 2.53.

Thank you!


Alex

 

[JAD]

There maybe a bios setting for enabling UDMA on the IDE channels, The slave
of the 2ndary may have it disabled
OR like you said but most of todays Opticls will use some level of DMA

 

[678]

There maybe a bios setting for enabling UDMA on the IDE channels, The slave
of the 2ndary may have it disabled
OR like you said but most of todays Opticls will use some level of DMA

Thank you for your reply!

I did a little bit of research after I'd posted and came up with one
method: re-install IDE2.

I went to Device Manager and keep transfer mode for both devices as "DMA
if available" even though current transfer mode says "PIO". Then right
click and choose "uninstall". After uninstallation of IDE2 is done,
right click on "IDE ATA controller" and choose "scan for hardware
changes" to re-install IDE2. Viola! Now both have current mode of
transfer in "Ultra DMA"!!


Alex

 

[Ed Light]

I know it wasn't your problem, but I have a drive which wouldn't do dma
until I updated the firmware.

 

[Ed_]

Thank you for your reply!

I did a little bit of research after I'd posted and came up with one
method: re-install IDE2.

I went to Device Manager and keep transfer mode for both devices as "DMA
if available" even though current transfer mode says "PIO". Then right
click and choose "uninstall". After uninstallation of IDE2 is done,
right click on "IDE ATA controller" and choose "scan for hardware
changes" to re-install IDE2. Viola! Now both have current mode of
transfer in "Ultra DMA"!!


Alex

Good for you. Now that you have treated the symptom of that disease maybe you
should examine the cause.

Most of todays optical drives will use DMA as default. If a drive records so
many errors within a certain time frame Windoze XP will reduce the speed to PIO
to protect the drive. Most likely your drive was recording some type of errors
when you were using it and this is why it was reading PIO.

The next time that you use that drive I suggest checking the event viewer in
systems managemant console to see if you are getting errors. It may have been a
fluke and never happen again but if it continues to revert to the PIO mode then
you have other problems.

This information is brought to you from an owner of a TDK velocdrw that now
functions correctly ( third TDKVelo drive I tried after RMA'ing 2 others).

Ed