> but a bit slow. cdrecordProDVD reported "DMA speed to slow) (OK for 8x) > but then the average write speed was only 1.5x ( for a chunk of 3.6Gb). > Is there any explanation for this?
Check DMA is turned on for the drive. Where did the image data come from? There can be problems with pipes, because of their limited buffer sizes. Did you master at the same time, or did you burn a mastered image (= single file)? Please verify the runtime(s) reported by the burning program with your watch or a wallclock, *NOT* the computer. > Second and most important, which media (format) should I use. > I need my DVD burner for backup only, so I don't need compatability > with any DVD-ROM. There are those who argue that DVD-RAM is the only useful one for backups, "because it was designed as a backup format". It does give you more or less unlimited overwrites, has the advantage of treating your media as a read-write harddisk (no mastering/burning required, but check the performance!!), and has an integrated verify. You might find the last point most important. DVD+-R(W) are consumer formats, reliability was not a design goal beyond making sure Joe User can watch his videos. They do work too though, but you *must* verify after each burn, especially for the erasable ones. DVD+RW is treated as read-write disk automatically by modern Linux distros (eg SUSE 10.0). Ie insert media, use cp - the automounter and kernel do the rest. In terms of DVD-ROM compatibility, there is no real difference any more, but there's still no guarantee that every media/drive combination works and you can expect some rejections, tendency declining. This is less a function of format, more of specific brand combinations. HTH, Volker -- Volker Kuhlmann is possibly list0570 with the domain in header http://volker.dnsalias.net/ Please do not CC list postings to me.
