second DVDRom device.

[siluet]

I want install additional DVD Rom (I have CDROm). What not clear: is there some shortcomings/drawback of using two CDRom/DVDRom devices on one PC? Meaning affecting on system stability, on motherboard reliability, other. Normal use supposes to have one CDRom or DVDRom device per motherboard, however.

[CrayonEater]

There is no disadvantage or problem. As long as it fits in your computer and your power supply is adequate, no problem. Lots of people have either a DVD burner and a second DVD-ROM drive (reader) so they can do copies, or two burners. Today, burners are so cheap few people bother with a DVD-ROM reader, and put two burners in. It's a good idea that at least one of the burners be a Master drive. If you have a SATA hard drive installed, you can set both burners as Master, one on the Primary IDE cable, one on the Secondary IDE cable.

[oldandinthe way]

Who says that's normal use. Many manufactuers package two optical drives.

Depending on the other devices on the system you may run out of DMA channels. If so make use the CD-ROM is uses PIO not the DVD.