Jörg, I don't care about silly arguments about who's right, but I have to agree 100% with Andy's assessment of the situation. He gave sound reason for his conclusion. I am still very interested in your detailed technical explanation on why a fast CPU with 0% load only manages a 0.4x DVD burn speed because of a lack of enabled DMA.
Further to the issue on hand, I have this hardware: Duron 600 00:00.0 Host bridge: Silicon Integrated Systems [SiS] 730 Host (rev 02) 00:00.1 IDE interface: Silicon Integrated Systems [SiS] 5513 [IDE] (rev d0) Vendor_info : 'PIONEER ' Identifikation : 'DVD-RW DVR-106D' Revision : '1.05' Seagate 7200rpm 8MB cache IDE disk (this is probably significant) which seems as close as we'll get to the system in question. SuSE 8.2, kernel packages k_athlon-2.4.20-100 and k_athlon-2.4.20-101.i586.rpm (I don't spend time on rolling my own kernels). Burning 4x DVD-R is just fine. DMA enabled. Three times now in the past 6 weeks I have observed the system suddenly running at what appears to be 10% speed. CPU load shows nothing significant, say <20% almost all the time, I think there may have been peaks too. Oh, and DVD+RW burning happens at 0.4x... luckily it was +RW, so I could just kill it. No funny processes I could find, nothing obvious in syslog. A reboot always fixes it. Usually I use the system via ssh + shell. It seems to get stuck after heavy harddisk activity (like cp a b of a 4GB file). It seems to be a kernel problem to me, hints as to further debugging appreciated... Looks like the kernel gets permanently stuck in the IDE department somewhere. Note there's a generation mismatch in the system: the mobo is late 99/early 00, the disk is mid/late 03. It's not unlikely that Linux simply isn't tuned for this particular combination. I have to agree with Jörg in one respect: on the above Duron 600 as well as on a P4-2GHz the kernel's idea of time, and therefore the calculation of burn speed, goes seriously bananas without DMA (but by factor of 2 in my experience, sample=2). HTH, Volker -- Volker Kuhlmann is possibly list0570 with the domain in header http://volker.dnsalias.net/ Please do not CC list postings to me.