is it possible to use nero to burn 1 x image to two disks in separate nec3520 drives at same time
Yes it is with recent Nero versions. Check the “use multiple recorders” box.
Then when the burn is actually launched you’ll be able to select the burners to be used.
A helpful hint…when I use two burners(benq 1620) at once, I find the best results at 8x. I find that even tho the burns will complete at 12x or 16x, there are plenty of buffer underruns and the quality scans suffer. I am ok with it as two discs at 8x speed take about 8-9 minutes, or 4 1/2 minutes per disc overall. However, give it a try and see what you come up with. My config is: P4-3.0C@3.6; 1GB@240FSB; sourceHDD=SATA RAID0; burner 1= primary master; burner2=secondary master.
I would recommend 4x, unless you want to push the limits. At 8x, most burners will be doing WOPC, which pauses the drive. But both drives will not be pausing at the same time, thus Nero will have to pause both drives to keep the burns in synch.
Try it, and watch your speeds and buffers closely. There’s no real harm in the burns being paused more than is ideal, but excessive activity can make a bad disc. It may not make any difference whether your burners are on one channel or 2, but again you have to try it and see.
Of course you always have the option of burning from 2 instances of Nero, but your HD may not keep up at more than 4x.
Just sharing some experiences…
When burning 2 discs at a time with Nero, the program has a column titled ‘Read Position’ that is just after the ‘Buffer Level’ bar graph. See screenshot. It indicates in % how much on disc is ‘ahead’ of the other. I think it is % of the 80MB buffer, since it can move about 10%/second when moving quickly, and that would correspond to about 10% of 80MB = 8mb/sec, about 6x burn speed, so definitely in the ~4x-8x burn speed range of the 8x burn strat.
The discs usually start out at 0% Usually it stays around 10-20%, often more and often less,(sounds funny, but there is no consistent spread) but never at 0% the whole way thru and never over 100%(which I think means the buffer).
Another peculiarity is that when the data portion of the burn is done, Nero closes one disc, then the other disc. It does not burn the ‘closures’ at the same time to each disc. That adds about 40 seconds to the total burn time of dual@8x burntime.
The burn results are usually a little worse for dual-disc@8x than single disc@12x, but the results are still acceptable. 90% of the discs I burn get a quality score of 96-98@single-12x, and 94-96@dual-8x. I haven’t tried 4x, because 2 single discs @ 12x would take about the same time, within a minute, so no speed benefit and a doubtful quality benefit.
However, everyones results will vary, and I feel that I get pretty good results with my setup, so you may not see as good of results as I get. Maybe you’ll get better results…I hope you do! As rdgrimes states, 4x is probably safer to start out with,