Lag after Editing

I record for Librivox and have been running into sluggish recoveries after editing longer files. I’ve posted there, but it seems like others aren’t experiencing the same problem so I thought I ask here:

So, here’s some stats:

Audacity 2.0
Windows Vista SP2
2.5 GHz dual processor PC with 4 GB of RAM)
(defragged! This was one of the Librivox suggestions - I’ve done it.)

The problem occurs after I’ve saved the file and come back in a subsequent session to edit. If I edit during the initial session I have not had problems, but with longer files especially I usually edit over several sessions.

Loading a 58 minute .aup file takes 1:18. If I delete 1/2 second of the file it takes 1:09 before I can continue editing. (Length of the edit doesn’t really matter. I get the same lag if I delete a minute as I do if I delete 1/2 a second.)

If I cache the entire 58 minutes piece into RAM it takes 1:14 for the file to load and another 2 minutes to copy the file into RAM. If I delete 1/2 second of the file it takes 1:09 before I can continue editing.

In other words, caching the file in RAM does nothing to help with editing and I actually lose time during the load.

A 9:58 file takes :15 seconds to load and :15 seconds to recover before I can continue editing if I delete 1/2 second.
A 25:00 file takes :45 seconds to load and :39 seconds to recover before I can continue.

Conclusion: there appears to be a nearly 1:1 relationship between how long it takes to load the .aup file and how long it takes to recover from an edit.

Following the suggestions on the Librivox forum I saved the file as a FLAC. The FLAC file imported in :50 seconds and recovery from the edit was essential instantaneous.

This reinforces my gut feeling that, once I’ve saved a file, Audacity is reloading the file after an edit, but I really don’t know what’s going on. At any rate it’s clear that, at least for me, the best thing to do with large files, pending a better suggestion from one of you, is to export as a FLAC and edit that in subsequent sessions.

Loading a 58 minute .aup file takes 1:18.

That’s one minute, eighteen seconds, right? Something’s wrong. I double click on an AUP file and Audacity opens and mounts an hour long show just under four seconds – with FireFox running and active.

You defragged, but did you error check? And while those tools are open, how big is your hard drive and how much room do you have left? The video people have a rule that at least 10% of your drive should be free at any time. That’s not an awful rule. So no fair trying to edit a 200MB show in 250MB of space. Audacity uses a very high quality internal sound format and stacks up multiple copies of the show during effects, so shows get very large in a hurry.


It’s always dangerous when people use the phrase “I opened the aup file.” You did that and then the aup Project Manager File opened up the _data folder with the thousands of sound and data snippets and then opened up all the attached and associated music files you used. So no, you did not open a 27kB “show.” You pushed the tip of the iceberg and then the rest of the ice showed up.


OK, let me see if I can provide more information. Yes, that’s 1 minute, 18 seconds.

Disk status: there are no errors shown and I have 54% of the disk free (216GB free).

The .aup file is 92KB and the data folder is 595MB and contains the following
a folder called e00 which contains
folder d00 which contains 224 1,037KB .au files (or smaller, there are a couple of files under 1MB)
folder d01 which contains 256 1,037KB .au files
folder d02 which contains 111 1,037KB .au files

This is a recording of just my voice, no sound effects or music files or anything else.

For comparison, the project that is roughly half that long (25 minutes) has an .aup file that’s 54KB and the data folder is 263MB and contains
a folder called e00 which contains
folder d03 which contains 184 .au files of various sizes - probably 3/4 under 1MB and the others 1,037KB
folder d04 which contains 156 .au files probably half under 1MB.

Again, just my voice, no music or sound effects or anything else.

Both (all) recordings:
Channels: 1 (Mono)
Bit Rate: 128 kbps
Sample Rate: 44.1 kHz

Hope that helps. If there’s other info that would be helpful just let me know!

I “always” export the file, that’s no matter what Audacity tell me to save or make copy of original etc. etc. I simply save the file in my chosen location then I can edit it.
By doing this anything happens to the software or Windows, the file is still there and working well also to add more precautions I even make a copy of the original so I won’t worry any editing goes wrong with it.

What’s the hard drive light doing while you’re waiting for the Audacity Project to load? What’s the screen doing? During the wait, could you go off and check email?

Which Virus Protection do you have and does it make any difference if you disconnect your network and suspend the Virus software? Will your machine pass a Microsoft On-Line Virus search?

Did you buy many, many filters and effects and are they all in the Audacity Plug-Ins folder?

Your drives are internal, right, not USB or FireWire drives?

Instead of launching Audacity, what happens if you double click on one of the aup files? Does Audacity take minutes to launch and then the show takes more minutes?

If you don’t have too many custom settings or favorite adjustments, we can try to reset Audacity. “Reinstalling” Audacity generally doesn’t do anything because most of Audacity’s personality is in the preference system. The actual program is decorative and dumb. You have to critically edit the preference file and restart Audacity.

This is when I get to sit in the corner and wait. I’m not on Windows.


You’ve been perfectly clear and helpful, and it’s crystal clear to us none of this should be happening. You have the simplest possible show and a reasonably powerful computer should be able to handle it while loafing in the back yard with a cup of tea.

I’m in la-la land now and if we can’t find anything else, I’m going to recommend a memory checker. Microsoft makes a very nice one and it’s free, but you do have to jump through some hoops to use it. Let’s see how resetting Audacity works out – if you’re willing to try that.

You did restart the machine at least once during all this, right?

Your symptoms as described in your original post could be caused by your anti-virus/anti-malware/anti-everything else software doing a scrupulously detailed check of the file and of all changes to it. I’d make Koz’s suggestion of disconnect from the Internet and disable the Anti-virus software a top priority diagnosis taks.

This appears to be it! I have my “My Documents” folder on a NAS drive. As soon as I copied the files to my C: drive the lag went away completely.

Thanks all! I feel a little silly for not thinking of this, but I’m glad it’s working again.