Searching the net and I found this trick, It may come in handy for someone.

I found this little gem on another site and thought I would share it with you. As most of you are aware, CD or DVD burners don't actually burn at the speed you have selected. Selected speed is the theoretical maximum and, surprisingly, rarely ever reached. The attached .reg file will force nero to tell you what speed it is actually burning at - I found it very interesting.

** I have removed the zip file - it does appear to be faulty. Copy and paste the file contents shown below and save as "nero.reg" or whatever name you choose (must have .reg extension) and then double click. **

EDIT: Here is the contents of the reg file:

Windows Registry Editor Version 5.00

[HKEY_CURRENT_USER\Software\Ahead\Nero - Burning Rom\Recorder]
"ShowSingleRecorderSpeed"=dword:00000001

Thanks to kev1952 for this trick