I generally edit 40 minute long lecture style MP3 files. I have an i7-8700k processor with EVO-960 NVME drive. I just upgraded from Sound Forge v11 to v14, but the save times for the 40 minute MP3 file continue to be about 40 seconds, as are the times for processing (normalize, compression, audio restoration, etc.). Processor and drive usage never exceed 25% and are generally 10% during processing.

Another quirk is that the longer I edit the file, the slower the mouse response becomes. I usually proceed through the file to remove dead space, coughs, and other artifacts. I often use CNTR-X with left hand as it is easier than pressing delete. It is difficult to quantify precisely, but seems as though the time from mouse operation to action increases from ~10-30ms to 100-300ms. If I save, or exit the file, this interactive lag build-up goes away.

I have noticed this problem in both v11 and in v14, which I purchased in an attempt to resolve this problem. Hoping there is an obvious solution I am missing rather than converting MP3 source file to another format and back again.