I am using Linux, and use for converting my FLAC files into AAC Foobar2000 under Wine.
Now I also converted the WAV made from the FLAC by the command line neroAacEnc Linux version.
I used -q 0.45 converting Classical music.
Foobar gave me a bitrate about 145 kbps, while the Linux command line version about 125 kbps.
I checked the commandline Win version both under Wine in Linux and then also in Windows XP SP3, as well as Foobar under Windows. The result was always about 145 kbps.
I have a Intel dual core CPU.

Has anyone experienced something similar?

Imre herceg

Differences between the 2 versions result from using different compilers and using different code in some places. However, this looks like a too big difference, might be a problem in some linux specific part of the encoder. I will look into it.