Page faults and Omnisphere 2

Hey Guys,

I got this response from Spectrasonics:

Page faults are operating system events. They are not bugs or flaws. A page fault happens when an application is running, and it is too big to fit into RAM, and some of the application is stored on disk. When the application needs to use some of the software/data that is out on disk (not in RAM) a page fault happens, and the operating system fetches the software/data from disk and put it into RAM (and pushes-out some sw/data from RAM to disk to make room). Page faults are normal and natural. They are most likely to happen when the application has a HUGE amount of data loaded (for Omni, that could be things like several instances; or large soundsources). Ideally, the application would fit entirely within RAM, and there would be zero page faults while running. But if the application is too big for RAM, page faults will happen naturally, and there is no real problem behind it. There are situations where a user could set the Omnisphere stream settings to inappropriate values which might lead to heavy page faults: for instance, if the user turned streaming to “Not streamed” on the Omnisphere system pane.

They also explained that Omnisphere is heavily optimized and has no memory issues that we are aware of, with a reminder to make sure that the OS memory configuration is set up properly on the end-users Windows system - which is why I’m summarizing and not including the full reply :slight_smile:

From what I read on your company thread, your users are not getting getting audio glitches playing Omnisphere or CPU spiking - that would be an indication that Omnisphere is struggling and in that case it might be helpful Omnisphere’s streaming parameters should be adjusted on the Omnisphere System pane.

Also, they asked if you’re getting problems with audio glitches that you get in touch with them so they can help resolve them.

Brad

Whose fault is it they are called page faults, anyway? There is no positive connection one could make with that term. (See http://www.thesaurus.com/browse/fault)

That person needs the pocket protector stolen from his lab coat and hidden in a sofa somewhere.

Terry

Thanks for that answer from Spectrasonics , Brad !

But that doesn’t explain why ,with similar setups and PC specs , we all get so different page faults count on the same plugin…
Soooooo mysterious !!! :wink:

I think the lower page faults readings on my setup might be due to me running a few of my plugins in 32-bit mode with jBridge, which as Brad clarified, and so any page faults in their separate process don’t get counted by Cantabile.

Either way, I would think as long as you’re not hearing any problems, and as long as the page faults counter isn’t going crazily high, it’s nothing to worry about.

Neil

Hi,

I just thought I would add my experience to this, whilst I am setting up my new gig computer and getting all of my soft synths on. I too noticed very high page fault counts which concerned me, so went searching on the community and found this thread.

I hadn’t realised that the sample loading that Omnisphere does when you load a patch is by default only a pre-load function, and the rest of the sample is streamed from disk. In the Omnisphere settings you can set the Sample Mode to “Not Streamed”. This will increase load time and memory footprint, but, when the Ominisphere GUI is closed results in minimal page faults being reported. I have 32GB RAM, so it surprises me that there are page faults at all, but I guess it depends on how Omnisphere is setup internally to use memory.

You could also set things back to streamed mode and increase the preload memory size to 10,000 samples and that reduces the page fault count. I also noted that the page faults were definitely a result of streaming in this mode. If you played a new key, you would see the page fault count increased drastically. If you played the same note again, the page fault count would be minimal as the whole sample is in memory.

Given The Cantabile load with Omnipshere is about 10% and the page fault count seems to have no adverse effect, I will probably keep it in streamed mode and see how I get on.

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Also, Omnisphere and Keyscape do background pre-loading so the page fault count can stay high for a couple of minutes and then start to settle down.

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I agree, also RAM goes down after some minutes after preloading.
This behaviour I recognize also on some other VST/soft synths.
But, I don’t recognize any issues on e.g. audiio dropouts, then playing direct
after preloading.