thanks for the quick reply bjkg.

i did read the scan data, i do use 80-conductor cable and cmos setup does indicate udma4. the fuji dvd-r that dont work at 4x but work at 8x are ritek f16 and the memorex dvd-r that work both at 4x and 8x are ritekf1 from nero infotool. i installed the latest miniport driver from asus for my dual-core athlon 4200+ motherboard. i have been a computer maintenance technician since 1979 when minicomputers had magnetic torus core memory boards. i understand that ata-133 interface gives 133 megabytes/sec bandwidth that is 6 times more than 16x 22 megabytes/sec burning demands. but still at 8x the drive led on the front panel turns on and off during the burn process. i know its ok because burnproof technology ensures that even if burning stops and goes the drive still comes out with a good dvd. i buy these brand dvds instead of verbatim or Taiyo Yuden because stores here have sales that i buy 5 or 10 100-packs at 22 $ (18 euros) each making for a price of storage of 1/4 of hard disks. verbatim are 100 $ (75 euros) for a 100-pack so i might as well keep my files on a 500 GB hard drive which costs about the same and has much faster access time. the way it's going, storage on terabyte drives will be cheaper than on quality dvds in a year, so a computer with a 3 terabyte raid-5 array (4x1TB) will be both affordable and as secure for data as dvd, while allowing instant access to files, so i probably won't even need sata burners. i appreciate all the help you give me, many thanks for this also.