About This Mac > ( More Info ) > Disc Burning
This is what my 2009 model says:
HL-DT-ST DVD-RW GH41N:
Firmware Revision: PQ05
Burn Support: Yes (Apple Shipping Drive)
Cache: 2048 KB
Reads DVD: Yes
CD-Write: -R, -RW
DVD-Write: -R, -R DL, -RW, +R, +R DL, +RW
Write Strategies: CD-TAO, CD-SAO, CD-Raw, DVD-DAO
Media: To show the available burn speeds, insert a disc and choose View > Refresh
You will get different results than mine if you have a different reader installed.
Sometimes the speed range is off.
In some media, there is a "up to 4.7x" media and an different "8x" media, and they are not cross-compatible.
Try doing what it says in the last line and insert one in your drive -- but be prepared for it to give you totally off-the-wall results for wrong speed range.