“It used to take 6 minutes to burn a cd but now it's taking 20”
The time it takes to burn a cd is dependant on the amount and type of data you burning to the cd and the speed of the cd-r
It is generally acknowledged as good practice to burn audio CDs at speeds no higher than 4x
Don't underestimate the importance of the chemistry of the CD-R itself.
Just like CD burners, not all CD-R are created equal and there is a significant difference in the quality of the media from different manufacturers, sometimes even from batch to batch from the same manufacturer.
All CDs are rated for a specific burning speed.
Some burning software performs an integrity test on the CD prior to initiating the burn sequence.
This test determines the CD’s speed capacity and can limit the burning speed.
If you try to burn a CD at a higher-than-rated speed, the burn will likely fail.
“I hear the tower making a "rushing" kind of accelerated noise every few minutes while it's burning”
These is normal noise as the drive start up and check the speed to burn to the disk