Slow data source

what does it mean when Nero decreases burn speed due to slow data source?

I was going to copy from the hard disk, and after record simulation Nero said that burn speed would be decreased to 24x because the data source was too slow.
Selected speed was 52x… The data source was a bunch of .AVIs (700MB).

ur “data source” is whatever ur data is being read from, which in ur case is ur hard drive. nero is telling u that ur hard drive transfer rate is too slow. check to make sure dma is enabled, and u might wanna defrag if u haven’t already done so.

anything apart from that?

There is a test to check the trasfer rate from the hard disk in Nero but I noticed the result will be cleared after I shut down. Should I do that always before burning?

And of course the trasfer rate is way higher than 52x on the CD-R… I wonder if anything else could cause the slow down? Could the .AVI files be the culprit?