Audacity Recording Freeze at 38m 47.5s: Win7

[audino]

You are not the first to misunderstand the purpose/implications of that option. Can you suggest better wording for the option?

In my opinion it shouldn't be under "Directories", what about creating a label called "Performance"?

[steve]

Thanks for the suggestion audino.

The option is under "Directories" because it is directly related to the "temp folder location" (which is quite rightly in the "Directories" section).
Normally Audacity will write data to this temp folder unless/until the project has been saved
When "Play and/or record using RAM (useful for slow drives)" is enabled Audacity uses RAM instead of the hard drive.

I think that moving it to a "Performance" section would encourage users to enable it when not needed and so lead to the problem that you had.

Perhaps something like "Disable hard drive cache".

Essentially the problem is that the feature does not work very well. What should happen is that when the memory limit is reached, Audacity should seamlessly switch back to writing to disk. Unfortunately it is not seamless. Obviously the switch needs to be very fast so as not to disrupt the audio data stream and it looks to my uneducated eye (I'm not a C+ programmer) like the problem lies there. It seems that sometimes the audio data stream gets disrupted during the "switch over" and that stalls the recording.

This is what the manual currently says: http://manual.audacityteam.org/manual/h ... html#cache
Could that be improved?

[kozikowski]

...useful for slow drives and short recordings?
Koz

[kozikowski]

As I said, I miss-undersood Koz's comment.

It's my job to be clear. It's a standing joke that I sometimes need a translator.....[frowny face]
Koz

[audino]

Thanks for the suggestion audino.

The option is under "Directories" because it is directly related to the "temp folder location" (which is quite rightly in the "Directories" section).

Yes that's right also I was wondering why there's only a temporary location but not a location you choose to save your files.
What I always do with any software I tell it to store any output to a drive/folder I created and use only for that purpose.

When "Play and/or record using RAM (useful for slow drives)" is enabled Audacity uses RAM instead of the hard drive.

From the Wiki "Minimum free memory (MB): Sets a minimum level for available system memory" this instruction is very clear but from the control panel I thought it refers to the system memory I tell Audacity to use as cache not the bare minimum left for the system to be alive.

I think that moving it to a "Performance" section would encourage users to enable it when not needed and so lead to the problem that you had.

Perhaps there are novices and experienced users, maybe a clear red warning when playing with that setting I think could be beneficial

Essentially the problem is that the feature does not work very well. What should happen is that when the memory limit is reached, Audacity should seamlessly switch back to writing to disk. Unfortunately it is not seamless. Obviously the switch needs to be very fast so as not to disrupt the audio data stream and it looks to my uneducated eye (I'm not a C+ programmer) like the problem lies there. It seems that sometimes the audio data stream gets disrupted during the "switch over" and that stalls the recording.

The default unchecked box should be enough for now, then if I know what I'm doing so I play with it and if things go wrong I set it back to default.

[otwo_pipes]

Apologies for not replying earlier regarding the request from Steve for new wording for this function. The delay was partially due to wanting to polish my words and partially due to weekend activities.

So, here are my efforts; I would suggest the following revision:-
Start with
This function is required for legacy PC hardware. Modern PC systems should not select the tick box. If in doubt try the default, 'Not Ticked' setting first.

Copy the current message 'as is' in this area, including the tick box etc. but remove the section in brackets (useful for slow drives) as this may tempt someone to try this feature which is the exact opposite of what is required. A better explanation of how this function works can be incorporated in the user manual.
and the crux is to finish with:-

WARNING: When this feature is enabled recording time is directly proportional to (free system memory)/(sampling rate)
and in red if deemed necessary....

Notes:
i) I know this feature is not dependent on legacy systems but the intention is solely to stop newbies like myself from making a basic error by enabling this function.
ii) I think it would be good to provide a list of the 'default settings' in the user manual but even better would be to have a save/restore function for the default and/or user settings. The 'restore default settings' would be particularly useful in situations similar to the problem discussed here; it would be possible to set everything back to the default and start again. A standard de-bug procedure.
iii) Koz was very clear. It is my professional ability related to reading English that was the fault (I am Welsh) and said with a big smiley face...
iv) I also thought I was setting the amount of RAM to be used as cache and not the true operation (same reason as iii) above. There is nothing wrong with the explanation it is just the function does not work as I expected and therefore I did not read correctly.
v) I have had no further problems with Audacity and, so far, I have transferred 28 albums to my hard drive.
br and thanks again to all
Dennis

[Gale Andrews]

@otwo_pipes, so did you have "Audio Cache" enabled on the XP system where you don't receive the crash?

Audio Cache is not on by default. Note that caching applies to editing as well (though I think there should be an option for it to apply only to recording). 96000 Hz, 24-bit recording takes about 33 MB of cache (or disk space) per minute, hence you have used about 1.3 GB of RAM when you crash (almost all of what you had left).

Audacity is 32-bit. Even if you had 3 GB of RAM, 32-bit Windows has a limit of 2 GB memory per application for a 32-bit application. So if you had not crashed during recording, you would have crashed if you had edited the whole of the recorded track (because that would have pushed the RAM use to 2.6 GB).

If you had 64-bit Windows, then the maximum memory Audacity as a 32-bit application can address is 4 GB.

Clearly Audacity can and does crash when RAM cache is enabled before the system RAM gets as low as 16 MB. That may be a problem of the default being too low, though I know some people find Audacity will crash with this feature on when the system RAM gets down to 600 to 700 MB. The developers so far have not shown much interest in looking into this, but may find they cannot reproduce the problem. With an old Win 7 64-bit system with only 2 GB RAM (therefore only just matching minimum requirement), I can repeatedly go down to 16 MB system RAM remaining and have Audacity then switch to disk writes with no crash.

On the documentation of system requirements, see http://audacityteam.org/download/windows#sysreq where it says the recommended Audacity requirement for Win 7 32-bit is 4 GB RAM (the maximum RAM you could install). Note however that even with 4 GB RAM installed, typically only 3 GB to 3.5 GB will be available for applications. We went for a 4 GB recommendation even for 32-bit Windows on the basis of experience with the previous 1.3 Beta series working with hour long recordings or more (irrespective if Audacity RAM caching was enabled). I'll make this clearer on the Windows 7 Wiki page.



Gale

[otwo_pipes]

@Gale: Yes, I had caching enabled on the XP system because I had mis-understood the purpose of the cache switch.

I have now repeated the XP system test and found Audacity grabs memory until aprox. 1.3 GB has been used. This equates to recording for about 35 minutes and then Audacity starts disc writes and I have not seen any problems. I left this test run for just under an hour. This repeat testing was using the internal sound card but the Audacity settings were still 24/96. The temp files stored on the hard drive for this test total aprox. 1.9 GB. If you want me to repeat with the high speed sound card then I can though I do not see what benefit this will give. BTW the 24/96 card is not no longer fitted in the XP system so I would have to re-install the drivers etc.; this will not be an immediate task though I could repeat the tests tomorrow evening.

My XP system is SP3 with 2GB RAM and a pretty slow Celeron processor. The system was bought second hand years ago so I guess it is`15 years old. My Win7 system is only 2 years old with a SATA II hard drive and is significantly faster than the XP system. I see regular 60% CPU usage on the XP system and only occasional CPU usage in excess of 20% on the Win7 system when Audacity is recording. I am do not use either of these systems for general computing when Audacity is recording though there is various security sw running. Both systems have a wired Internet connection.

If I can be of any further assistance, or there are any tests you would like me to undertake, then please point me in the right direction.

[Gale Andrews]

@otwo_pipes, all images in the Manual show default settings unless otherwise stated. I'll add your vote for some way to reset to the Audacity defaults from within the Audacity Preferences. At the moment, reset is done by editing the audacity.cfg settings file (see http://manual.audacityteam.org/o/man/pr ... tml#stored ).

I tried to tweak the Manual page for Audio Cache ( http://manual.audacityteam.org/man/Dire ... nces#cache ) - the wording for "Minimum free memory (MB):" now says "Audacity will use RAM until your total available system memory falls below this level, then will write data to disk instead".

If you want to test on the Win 7 machine, I would be interested to know if you avoid crashing if you set "Minimum free memory" to about the system memory you have left before the crash. Is this about 600 MB?



Gale

[PGA]

At the moment, reset is done by editing the audacity.cfg settings file

Or during install of v2.0.1 if the box is ticked!