Enabling DMA did increase the write speed, but it seems to have caused a major problem. After enabling dma, I started having "delayed write errors" during ripping with DVD decrypter to my SATA hard-drive. In the middle of the rip, the SATA hard drive would disappear and I would get the "delayed write error". The SATA drive would come back after I restarted my computer. I tried several things, like defragging, drive error checking, looking for new drivers, etc. before disabling dma. After disabling dma, I made it through my rip without the error.