HELP!! I've burned CD's in linux before with great success, but I've upgraded my hardware and am beginning to have speed problems. Previously, the fastest burner I had was 16x, which worked fine at full speed as long as DMA was enabled. I've recently purchased a Plextor 712A, which will burn CDs at up to 48X (along with DVDs at up to 12X, but one thing at a time!). When running cdrecord, I now have to enable 'burnproof' to prevent making coasters, and I never seem to be able to write at more than about 25-28x. Dma *IS* enabled: naibed:~# cat /proc/ide/hda/settings name value min max mode ---- ----- --- --- ---- breada_readahead 4 0 127 rw current_speed 66 0 70 rw dsc_overlap 0 0 1 rw file_readahead 0 0 2097151 rw init_speed 12 0 70 rw io_32bit 1 0 3 rw keepsettings 0 0 1 rw max_kb_per_request 64 1 127 rw nice1 1 0 1 rw number 0 0 3 rw pio_mode write-only 0 255 w slow 0 0 1 rw unmaskirq 1 0 1 rw using_dma 1 0 1 rw The data is coming off a SATA drive (mounted as /tmp...no other system activity to this drive) which should have more than enough bandwidth (53M/s reads): # bonnie++ -u root -d /tmp Version 1.03 ------Sequential Output------ --Sequential Input- --Random- -Per Chr- --Block-- -Rewrite- -Per Chr- --Block-- --Seeks-- Machine Size K/sec %CP K/sec %CP K/sec %CP K/sec %CP K/sec %CP /sec %CP naibed 1G 12878 67 41023 8 22196 4 19980 70 53342 8 238.4 0 ------Sequential Create------ --------Random Create-------- -Create-- --Read--- -Delete-- -Create-- --Read--- -Delete-- files /sec %CP /sec %CP /sec %CP /sec %CP /sec %CP /sec %CP 16 11134 19 +++++ +++ 5433 11 4758 26 +++++ +++ 1942 8 The system is a 2.4G Athlon on an Asus A7N8X (NForce2) motherboard, with the burner hooked up as the primary PATA master, and 4 SATA 160G drives hooked to a promise TX4 controller (on-board SATA controller is diabled via jumper). I'm running debian-testing (sarge) with the stock debian kernel: 2.4.26-1-386. The only kind of odd thing I'm doing is using the ATA support in cdrecord to talk to the burner rather than SCSI emulation (I was having problems getting that going...apparently I don't yet fully understand the interaction of the new libata and the "hda=scsi" kernel command line parameter). The actual cdrecord command I'm using: cdrecord dev=ATAPI:0,0,0 driveropts=burnfree speed=48 -dao -v image.iso ..after which I get a report typically listing ~30 predicted buffer underruns that were prevented. It seems like this system ought to be fast enough to burn at 48x without any buffer underruns...any suggestions for settings I can tweak or other tests I can run? -- Charles Steinkuehler charles@steinkuehler.net