hmm i think i figured it out, i burned a dvd (4.6 GB), in 6-7 minutes wich was on my external HD. But when i burn an on-the-fly compilation the burning goes too slow. This could have 2 reasons:
-I printed a table from the internet wich says wich DVD media is recommended for the NEC ND-3540, DVD+r (Brand: verbatim) what i'm using is not on the list of recommened media for DVD+r at 16x, only Taiyo Yuden.
-I checked with NeroInfotool at wich speed my DVD-Rom can read, it's only 8x ! So that explains why it takes almost double the time instead of a compilation from HDD to DVD.
I think it's not the DMA, because DMA Mode 2 is 33.3 MB/s, 16x is 22 MB/s, so that should be okay.
About the firmware, i think i do not need to update the firmware, as phil_ and i where unable to find a firmware update, there is one, but it was not made by NEC.
Phil_, i also think a defrag might help, because al my partitions are almost out of free space.
I think my problem is solved, so if i would buy and install a DVD-Rom wich can read at 16x, should an On-The-Fly compilation also be finished in about 6-7 Minutes?
Anyway thanks for the help guys, really apreciate it!