I've grown accustom to having two internal Hard drives and was
wondering if it's possible two also have two cd-rom drives
as well,say one cdrw and the other a dvd burner-i know
you can get a all in one Burner but i'd rather use two different
burners.

Assuming your Hard drives are IDE and not SATA, then you have a maximum of 4 that you can attach to a standard MB (i'm not aware of any MB that handles more than 4, however I have seen some micro ATX MB that have only 1 IDE port).
If you that then try to have your burner on a different IDE port than the HD that you normally burn from. IE - IDE Port 1 - master=HD1 - slave=DVD, IDE Port 2 - Master=HD2 - slave=CD burner

If you want to add more then you will have to add a PCI IDE add-on card which will give an additional 2 IDE ports (4 devices)

I've got two IDE ports on my Elitgroup K7S5A. There are two harddisks connected to the faster IDE100 and one CD-Burner and a DVD-rom to the slower one. And it works fine

My configuration (works good):



It would be better to have the DVD-ROM on primary slave. It is better when you try to make copies on-the-fly.
Anyway, I have read somewhere that it is best to put your CD-Writer as master, as it gets a higher priority. A very good configuration would be (IMHO):

Most motherboards support your subject configuration. I have several computer workstations running different operating systems with this configuration and have no problems. The newer your equipment and software, the less likely you will have any problems. Consult your motherboard manual.

Is there any truth to the rumour that a CD-ROM drive on the same bus as a HDD can
compromise the HDD's speed?

I've heard it's true, and I've also heard it's false (it would be rumour from the bare-IDE-that-was-not-E-IDE days).
Anyway, master and slave share the same connection, and won't send data at the same time. It is one or the other. Now, I don't know if this have an impact on the transfer rate, the IDE being possibly fast enough to handle both request before the devices want to send the following data.

Some Mobo can handle more drives. I've got an MSI K7T266 Pro2 RU, and you can put 8 IDE drives on it, 4 of them being necessarily hard drives, thanks to the 3rd and 4th IDE ports, that support RAID, but don't support CD ROM drives. I nonetheless don't use them because booting with a hard drive on these ports is endless.

I suggested the HD2 be set as IDE Port 2 - master because i have incountered on some setups that the MB doesn't like it when a non-HD is found as the master.
If it works for you then good - just check it with some software to see if your HD throughput is diminished. I had one setup where the HD (slave) was registered on the system but the throughput was 1/2 of what it was capable of.

Most CD/DVD drives are UDMA, 33MB/sec. devices, and so they can do on-the-fly copies on the same data cable easily (as long as the software you're using has some sort of caching enabled). Hard drives, on the other hand, may benefit from being on separate cables because they transfer data so dang fast, and because two drives cannot communicate at the same time on the same cable, IIRC. If you make DVD backups, there's a chance that putting the DVD drive on a separate cable from the HDD will help speed things up, but I've never tested this idea, so it could be malarkey.