Random Buffering(?) Gaps In Recordings

I am posting this under ‘Windows’ (rather than under the Audacity version specifically) because we’ve only had this problem since upgrading to Windows10. I can’t see it having already been reported anywhere else on the Forum so maybe it’s a new bug related to Win10 or how Audacity interacts with it?

We have been running Audacity 2.2.2 under Windows10.0/Pro/Build17134.345,x64,4GB RAM,3GHz,111GB freespace drive C. When the problem first occurred we were running version 2.0.5 (under the same Windows version) which is why we upgraded to 2.2.2. Prior to Win10 we did not have the problem at all on any earlier Audacity or Windows versions.

The problem: During recording we sometimes see ‘gaps’ in the audio (flat-lining), of one or more seconds, spread randomly through the track, with a message overlaid in an error-window “Recorded Audio Was Lost At The Labelled Locations. Possible Causes: other apps are competing with Audacity for processor time; or you’re saving to a slow external storage device”. The message then sits there (while the recording continues) until the user chooses to stop the recording.

No audio is actually being missed; if (after hitting Stop) you laboriously close the gaps up manually during editing (ie select the gap-section and delete), the sound is perfect; it is all there, the apparent audio ‘gaps’ are bogus. That’s why it seems to me to be a buffering delay or lag of some sort.

This PC is not on the internet or even a LAN, ie it is completely standalone. I have checked Task Manager on some of these occasions and all the readings have been low, nothing yellow-highlighted, and most times Audacity is the only user process running!

I replaced the entire PC with one having the same specs (ie the same Audacity/Windows versions) and we got the same problem.

The problem seems more prevalent when doing longer recordings (say 1-2 hours in duration) but we have had it on shorter recordings also. Another peculiarity is that we’ve experienced it far more often on music passages, as opposed to spoken passages.

I have not been able to pin down what brings this problem on. It is completely random and unpredictable. It might happen 3 times in 4 days (as at present), or we might be free of it for 3 weeks or more.

In a normal week, we would use Audacity up to 10 times daily, Mon-Fri, and it is also used to a lesser extent at weekends. So we are regular Audacity users and 95% of the time have no problems with it. Apart from this one random issue!

We have now upgraded this PC to version 2.3.0 and will wait and see. However, I have read the bug-fixes for the latest release and couldn’t see any mention of a problem like ours, so am not particularly optimistic.

Do you or anyone have any clues as to what might be causing this? Any suggestions on where to look or what to try next? I hope I’ve provided sufficient info above, and any assistance would be greatly appreciated.

Thanks!

My first two guesses would be:

  • Windows update is running in the background
  • Anti-virus application is either updating or scanning.

Either of these processes can shut out other applications, even if the CPU load / disk usage appear to be low. This can usually be avoided by:

  • Force update at convenient times (regularly)
  • Manually run anti-virus scan at convenient times (regularly)
  • Schedule updates and scans at convenient times (such as night time) and ensure that the computer is powered on at those times.

A quick troubleshooting note: I know the goal is to make it perfect, but don’t ignore the conditions if you find a way to make it worse. Any abnormal conditions or symptoms will produce valuable information.

You can still manually defragement the drive. Is it spinning metal or solid state? SSDs don’t need defragmenting and you can actually cause problems by forcing one, but Spinning Metal drives doen’t always take care of themselves. When they fragment, they they slow down.

https://www.laptopmag.com/articles/defragment-hard-drive-windows

Or Google.

Koz

Thanks steve/kozikowski for the replies.

My feeling is that fragmentation is not the problem here. Current stats for that drive are: C partition = 150GB, 67% free, 6% fragmented; D partition = 1.8TB, 98% free, 0% fragmented. The pagefile (8GB on Drive C) is contiguous and, as you can see, there’s plenty of other free space for Audacity work-files and suchlike.

It’s a Seagate Barracuda spinning/metal drive. Two separate bits of software both report the drive to be in “good health”. And in any case, this is the second PC with the same issue. So, probably not the HDD itself (in my opinion).

I will adjust the “quiet hours” for Windows Update, although with it being disconnected from the LAN/internet, I doubt whether it’s actually doing any automatically. (I do manually connect it at regular intervals so it can do its updates, then disconnect it again. The disconnection thing is an attempt to narrow down the problem by eliminating any task initiating via the LAN. Once I’ve solved this problem, it can be permanently reconnected again).

The anti-virus angle could be a possibility though. The update/scan are both set to happen overnight, but the same comment as above, applies here too - it won’t be updating overnight if it can’t reach the LAN/Internet. I must admit that we do power that PC off at night, so any AV maintenance will be happening on power-on, say at 8am. Can’t say I’ve noticed a trend for this problem to happen in the 8am period in the morning though. Middle of the day is a more common time (but of course not always). As I said previously, it seems random and is certainly not predictable.

At one stage, I did a +4hr test recording in Audacity and started up a range of hungry other software alongside it - Audacity never missed a beat! So it’s not like we can even bring the fault on to diagnose the cause.

I will play around with the AV timings and suchlike, and in due course post what outcome eventuated. If you have any further suggestions, please keep them coming. Happy to try anything if it leads me to the solution.

Thanks for your help so far.

I agree that is unlikely. The disk has to very badly fragmented (or less than 10% free space) before there is much noticeable reduction in performance.

In that case, it’s probably not doing an update, but it could still be trying to do an update if it has gone past a scheduled update time. Also, as you’ve probably noticed, some Windows 10 updates are enormous, and take ages to download, ages to install, ages to shut down the computer (“Don’t turn off the computer”) and ages to reboot after the update. It’s one of the things that really annoys me about Windows :imp:
Fortunately, when it is fully updated, it keeps quiet … for a while.

I much prefer to do so too. Fortunately I mostly use Linux, so I don’t have to worry about such things. About the only thing I use Windows for is testing the Windows version of Audacity.

Diagnosis is often the hard part, especially for intermittent problems. It’s often a case of ruling things out one by one until the culprit is found.
At least Windows 10 has a reasonably good Task manager - It’s worth dragging that up straight away when performance issue occur.

I agree drive fragmentation issues are unlikely.

What’s the job? All that and nobody once said what the job was and what you’re recording.

How did you transfer your job between machines? Did you build both machines?

I’d be a lot happier if you didn’t have one drive with multiple partitions on it. Sometimes Audacity has a hard time getting enough speed from one drive much less one drive trying to service multiple clients. This stuff is all real time. There is no “Wait a second while I shift to another task.

I know this is borderline insane, but can you try this on a third machine? One that’s not carbon-copy identical.

Koz

I think there’s a video version of this problem. There was a computer and external drive combination that was dead simple and obvious for video production use and really popular with people shoveling high volumes of work. It was also marginally unstable and featured crashed work every so often seemingly for no reason.

The elves on that forum had enough reports of failures over time we started to discern the pattern. It did take a while because failures only seem to happen when the humidity got over a certain number on an even numbered Thursday. Developers call these “Moon Phase Errors.” It wasn’t a brand or product, it was the configuration and nobody else had this problem.

So depending on your answer to the microphone question, if it fails on a third machine, the microphone or connection may be erratic, and if it doesn’t then there is something common between the first two causing it. Particularly if both of them have partitioned drives.

I like your idea of making the machines busy and see what happens, Terrific idea, but did you also try to busy up the other partitions?

Windows used to come in a server version designed to do these tricks seamlessly. Does Windows 10? Is there an enterprise version?

I also had an eye-opening experience with drives. One of the Systems People had a very similar machine to mine except I had an SSD and he had spinning metal. I regularly cranked out video and audio production at will. I don’t recall any quality errors for a very long time. I sat down at his machine to do a simple job and I thought his machine was broken. “No,” he said, “That’s about the right speed and response.”

That’s not good news…

Koz