DMA and Mode 2

[Guest]

I recently upgraded my hard drive. In the process I had to upgrade the BIOS to recognize DMA 100. Could this effect a CDRW that is Mode 2? What is the relationship to DMA and Mode?

I have a Liteon 8X 4X 32X. The hard drive is a Western Digital 40 gig/7200.

Since making the change, the CDRW has been balking at recording at anything but slow speed.

Thanks for the help.

Best regards, Paul

 

[Arbee]

DMA stands for Direct Memory Acess - meaning that a device has access to system memory bypassing CPU, thus lowering the resources needed.

Previous ATA implementations worked in PIO modes (up to PIO4 - 16MB/s), and newer ones in DMA modes (UDMA2 is 33MB/s, UDMA4 is 100MB/s AKA UDMA100). Mode2 equals UDMA33 (a DMA access) - and updating the board firmware can cause issues in non conforming DMA devices.

The problem is that most older (1 year +) CDRWs don't support DMA mode properly - and cause various types of issues (crashes, system hangs, BSODS,...). Try to deactivate the CDRW DMA mode in Windows and burn at full speed.


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