Problem With Using Two DVD Writers

Hello, guys, i recently bought two ASUS DRW I814BL DVD Writer. So i need to write two dvd image at same time. But when i write use two writers at same time, Nero’s Buffer Level down between 14%-99%. (both recorder)
Write only one recorder no problem.
I have four SATA hard drive and connect my two recorder on Secondary IDE channel. How can i solve this problem. (sorry for my english) Also i used good quality DVD-Rs.

If both of the drives are on the same IDE channel, you can’t solve the problem, it’s a limitation of IDE. They need to be on separate channels for any chance of simultaneous burning to work without buffer problems.