Enabling Direct Memory Access or "DMA" for faster DVD copying
Checking and setting the DMA settings is an important part of configuring PC for recording DVDs.
From Microsoft:
"Basically, DMA or Direct Memory Access is a system that allows devices in your computer to transfer data
directly to and from RAM without having to use the CPU as an intermediary. This boosts the performance of your PC
significantly as not only the device from which the data is being read responds quickly, but also leaves the most
important component, the CPU, free for other critical operations. However, the UDMA or the Ultra direct memory
access is further advancement over the DMA technology that uses even higher data transfer rate thereby boosting
the overall performance of the PC.
For repeated DMA errors. Windows XP will turn off DMA mode for a device after encountering certain errors during data transfer operations. If more that six DMA transfer timeouts occur, Windows will turn off DMA and use only PIO mode on that device.
In this case, the user cannot turn on DMA for this device. The only option for the user who wants to enable DMA mode is to uninstall and reinstall the device.
Windows XP downgrades the Ultra DMA transfer mode after receiving more than six CRC errors. Whenever possible, the operating system will step down one UDMA mode at a time (from UDMA mode 4 to UDMA mode 3, and so on).
If the mini-IDE driver for the device does not support stepping down transfer modes, or if the device is running UDMA mode 0, Windows XP will step down to PIO mode after encountering six or more CRC errors. In this case, a system reboot should restore the original DMA mode settings.
All CRC and timeout errors are logged in the system event log. These types of errors could be caused by improper mounting or improper cabling (for example, 40-pin instead of 80-pin cable). Or such errors could indicate imminent hardware failure, for example, in a hard drive or chipset.
Let's take a look at enabling DMA in a computer using Windows XP.
To get started, you need to first open the Device Manager.
There is more than one way to do this, I will describe two.
Method 1:
- Click Start and Open Control Panel.
- Click on "Performance and Maintenance".
- Click on "See basic information about your computer".
- This will open the System Properties menu.
Method 2:
- Click Start and then click on My Computer.
- On the right, find the Systems Tasks menu and click on "View System information".
- This will open the System Properties menu.
Click on the Hardware Tab.
Click on the Device Manager button.
Here is the Device manager menu. Find the "IDE ATA/ATAPI controllers".
Click on the plus box to expand the menu.
Once it opens you should have a list similar to mine.
Here is the Secondary IDE Channel. Lets check it first.
Double Click the channel.
This opens the Properties menu.
Click the "Advanced Settings" tab.
This is where the IDE channel transfer mode is set.
Note the "Current Transfer Mode" box. This is your current setting.
Click the Transfer mode dropdown menu.
Here you can see the available transfer modes you can choose from.
Select DMA if available.
NOTE:
There are two devices on the secondary IDE channel.
In this case, the first device (Device 0) is my DVD ROM drive.
The second device (Device 1) is my DVD writer
Lets check the settings for the second device.
As before, use the dropdown menu to change the mode setting.
Set the transfer mode for the second device to DMA if available.
That completes the process of setting the tranfer mode for the secondary IDE channel.
Finish by clicking on OK.
Lets do the same procedure on the Primary IDE buss.
Click on the Advanced Settings tab.
Select "DMA if available" from the dropdown menu.
Device 0 on the Primary IDE buss is now set to DMA.
This happens to be a hard disc drive.
No other devices are located on the Primary IDE channel so that completes the process!
Select OK.
