DVD Burner speed trouble on FC4

Dear sirs, I’m using a DELL Latitude D810 with a DVD Burner. I installed a FC4 (full installation), and I upgraded it using yum. So I’m running 2.6.12-1.1398-FC4 My DVD Burner is a NEC DVD+-RW ND-6500A. By doing this test: Copy a 2Gb file from the DVD to the harddisk. On windows: 4minutes 3 seconds On linux: 27 minutes. hdparm –I /dev/hdc tells me that DMA isn’t activated… hdparm –d 1 /dev/hdc tells me that I’m not allowed to activate DMA on the DVD burner… Why ? How to bring my DVD to work on linux as on windows ? Best regards, Michel MENGIS__________________________ POSEIDON Project Manager EPFL - DIT - DIT-SB Ecole Polytechnique Fédérale de Lausanne Swiss Federal Institut of Technology Lausanne Tel: (+41) 021 693 2266