FAQ, tips and tricks - DMA

Description of DMA mode :

• The transfer mode for IDE devices has traditionally been PIO (programmed I/O) where data is transferred to and from IDE devices via CPU instructions. This mode is straightforward and simple but uses large amount of CPU time.
• When DMA mode (Direct Memory Access) is activated, the transfer is done without using the CPU - the CPU only sends the command to the CD-ROM drive and the whole transfer is done without the CPU's help and therefore doesn't take any process time.

How do I activate DMA mode in Windows 95/98/ME :

In Windows 95/98/ME DMA mode can be activated/ deactivated for each device.

• To activate you should start the device manager (Start -> Settings -> Control Panel -> system), select "Device manager"
• Now expand the "CD-ROM" and select your Plextor, "Properties" -> "Settings" and activate the "DMA" button.
• If "DMA" switch is greyed, the busmaster driver has not been correctly installed

How do I activate DMA mode in Windows 2000/XP :

Under Windows 2000/XP the DMA mode can be activated for each controller.

• To activate you should start the device manager (Start -> Settings -> Control Panel -> System -> Hardware) select "Device Manager".
• Now expand the "IDE ATA/ ATAPI Controller" and select your IDE channel, now right mouse button -> "Properties" and select the tab "Advanced Settings".
• Within the boxes "Device 0" and "Device 1" you can select the "transfer mode" for the particular device attached to the channel. Change the transfer mode to "DMA, if available" to activate the DMA mode.
• You can find the currently used transfer mode under "Current transfer mode".

After updating the firmware revision of my PX-708A using my Windows XP system the drive reads much slower. How can I resolve this?

Verify that your drive is configured in windows XP using DUMA 2, it is possible that after a firmware update the drive data transfer mode is changed to PIO MODE 4.
This can reduce the drive's performance dramatically.
Simply change the setting of the drive to UDMA 2 and restart the system.
Your problem will be resolved once the drive is running again in UDMA 2 mode.
If this doesn't resolve your problem contact Plextor support (Contact form)