-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 HI everybody, Here are the results of my benchmark. Your mileage will probably vary. Liars figure and figures lie. Past performance is no indicator of future performance. Yadda yadda yadda. :-) NEC 3550 DVD burner from Newegg - ------------------------------- - ------- Read DVD no-dma DMA off (hdparm -d0 /dev/xxx) time dd if=/dev/xxx of=/dev/null 3.9 MB/sec steady at that rate - no variation due to physically larger tracks Read DVD dma DMA on (hdparm -d1 /dev/xxx) time dd if=/dev/xxx of=/dev/null 11.52 MB/sec varied between 8-15 MB/sec as the benchmark progressed there was a definite "cliff" from 15 MB back to 8 MB partway through the benchmark, and it increased back up to 15 MB I didn't notice (audibly) if the drive slowed down. Both reads were 9GB dual layer DVD - ------- Read CD no-dma 3.6 MB/sec (level data rate) Read CD dma 5.03 MB/sec (increasing data rate) - ------- Write CD no-dma K3b burn an ISO image of 700 MB K3b reports 24X average write rate gkrellm looks like around 3.9 MB/sec (eyeball) Burn takes around 4 minutes (approx) Write CD dma K3b burn an ISO image of 700 MB K3b reports 37X average write rate gkrellm shows increasing data rate Burn took around 2 min 15 sec - 2 min 30 sec (approx) - ------- Summary: It turns out that I did not have DMA enabled on this drive. Why? Heck, I don't know. Now that I have dma enabled, and it runs reliably, I'm going to leave it enabled since the performance is MUCH better. Later, Andy - -- Andy Stewart, Founder Worcester Linux Users' Group Worcester, MA, USA http://www.wlug.org -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.5 (GNU/Linux) Comment: Using GnuPG with Thunderbird - http://enigmail.mozdev.org iD8DBQFEQFNTHl0iXDssISsRAh5BAJ0bCDa7eIpvGX6dAyUTsXNaKRF3bgCfZjIL hckU/pg9Ux+9pSYjPfOJbhc= =fizg -----END PGP SIGNATURE-----