effects - amplification : too slow ?

We haven’t used SVN since Audacity 2.1.0. We are currently working with the source code for Audacity 2.1.2.

Is there a question buried in here somewhere?

I think this is the first time you have said how much disk space you have (or had), but 10 GB is not very much. As you say, three Amplify passes on your 30 minutes of audio would take 1 GB.

In any case, is not Audacity waiting for the audio to process before writing each block file? Would you say that running an audio effect is a fair comparison with your test program?

As I said, Peter found Amplify slow in 2.1.0 but not 2.1.1. I don’t think there was any code change in 2.1.1 that would account for Amplify being slowed up, but not other effects. So perhaps there is some cause of variability in Amplify that we don’t know about.

If you point us to a cause of variability in Amplify or a reason for an Audacity slow up on your machine, then we’ll be grateful, as we will if you address the issues in the RAM write feature.

As data points, how long it is since you rebooted, are many other Disk I/O-intensive processes running, and are any other apps that write data to disk slower than you have reason to expect?


if you never used the profiling tools of visual studio which appear to be very cool (sampling mode where the program is stopped every 1ms and the call stack is recorded, or the instrumentation mode where it also adds some statistics recording code at the beginning and the end of each function) I guess it could be useful for you.

I still hope to find a way to multiply by 2 the performances of the amplify effect just by modifying some non-optimized loops, I’ll post the results I obtained with the perf analyzing tools, in every case I will have learnt many things.