I've just got a NEC 3520A and flashed to LD3520_1UF firmware. The writer plays DVDs and CDs fine, its just burning seems to be an issue. I have an Athlon 1400 on Asus A7A266 mboard with 512MB running Win2K-SP4.
When I try to burn a 4GB ISO to my Verbatim 16x (MCC004) discs at 16x in Nero the read memory buffer drops to 50% and the writer buffer seems to go empty quite a lot, presumably meaning my PC can't get the data to the writer buffer quick enough, which I know will kick in the buffer underrun.. I also noticed Nero was using up all my free memory, so I changed to using Alcohol, and then decided to burn the same ISO to a disc at the lowest speed of 2.4x, which has produced the included performance graph. Should the dips from 2.4x to nearly 1x be happening? Surely my PC is quick enough to move data at 3324KB/s and thus the graph should be just a smooth line right? I benchmarked my primary HDD, it can do up to 60MB/s, and it is defragged fully.. I'm convinced the I/O on my motherboard is to blame for this strange behaviour.
In short, if I attempt to burn a disc at 16x the buffer underrun is always kicking in and disc quality scans in cd-dvd speed have been as low as 40% in one case, burning at 2.4x seems to produce discs of quality 97%.
I'm just lost at to why my PC cannot burn at higher speeds? and DMA is indeed enabled.
Any ideas, pointers to look out for or time for a new PC?