Processing Speed

I am using Audacity 2.0.3 on a Mac using System 10.6.8. I am working with 50MB MP3 files. I have 0ver 100 GB file space available and over 8 GB memory available.

When I generate “silence” over a 5 second period or use the effect “fade in” or “fade out” it takes about 3 or 4 seconds to finish processing. However if I click on another application’s window immediately after applying the effect, it is applied almost immediately. Is there an Audacity or system preference that needs to be changed to gain this speed when Audacity is in the foreground?

Does it actually apply, or does the graphic just get out of sync with the effect? This disconnect isn’t unheard of. “The blue waves are there, how come I can’t hear anything.” The blue waves are a separate process and in a recorded Project, they’re actually separate files.

Audacity doesn’t edit MP3 files, so the show is more like 1GB in memory – or maybe more – while Audacity is working. (uncompressed show plus the effect plus UNDO). This is why we’ve been known to recommend breaking a very large show up into smaller chunks for production and effects.

Do you have an SSD or spinning rust? An SSD can make a huge difference in production speed. A friend at work and I have similar machines only I have a smaller SSD and he opted for the larger spinning drive (I’ve never filled up my drive and he’s a data hog). I’m going, “Dude, what’s wrong with your machine” when I tried to use his to do something simple. Slooooooooow.

Are you making new MP3 files when you’re done? Audacity has to make a whole new MP3 file when you’re done and the bubbly compression damage doubles when you do that… If you’re not doing anything complex, it’s usually best to use a pure MP3 editor instead of Audacity. We have recommended SM3SPLT. I know I’m supposed to push Audacity, but it doesn’t do anybody any good if the show at the end sounds funny.


Processing speeds up when Audacity is in the background and another application (e.g. Textedit) is in the foreground (only for some effects and when generating silence). As you suggest, this may just be a graphics update lag with a large file. I am new to Audacity and thought there may be a setting I missed. Couldn’t find anything in FAQs or tutorials.