cd-r/rw does not burn at proper speed

I have acually sort of two questions.  Im trying to put 2 burners on one computer and burn atthe same time.  Amd athlon 1 gighz, 256 ram, 7200 rpm hard drive.  32 speed cd burner.
When i burn one cd ;the max it goes when i do a speed test is 16x because it says that the information isnt coming in fast enough.  I use nero and made a picture image of a disk and burn it to cd through the hard drive so it can be faster.its a vcd.
 Any suestions on how to fix this?  I called the hard drive company Western Digital and they said the hard drive is fine.  They suggested the mother board may not being able to handle it.  Any help would be great.
2nd queston is that when i burn two cds at once. it takes 14 mins for them both to be completed.  It takes 10 mins for one.  Im figururing that the times is longer because they share a wire?  help please, ....