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I was umming and arring if this is the right place to post this, however the FAQs say this site applies to software and recording, amongst other things.

I've recently started recording a certain Java based video game on my PC - along with audio commentary - using 32 bit Bandicam and Audacity for microphone input. My computer is as follows:

  • Windows 8
  • 3GB DDR2 RAM
  • Core 2 Duo CPU
  • 256MB RAM graphics card (nVidia of some sort, few years old)
  • 120GB 7200RPM SATA drive - OS
  • 1TB 7200RPM SATA drive - Videos

I've been tweaking settings in my graphics control panel and within the game to get the FPS up. Finally I got to the point where I could comfortably record at 30fps. Yesterday, I installed Microsoft Office 2010 and VMWare vSphere for work purposes (sometimes I work from home). These had large installation files and fragmented the machine a bit - I ran a defrag and everything seems OK.

Unfortunately since then, my framerate will start around 40fps when recording and drop over 5-10 minutes to 30-40, then 20-25, then around 10-15 and stay there. This persists even if I stop the recording and start it again; When not recording I have the game set to limit to 60fps, which it sits on quite comfortably. Closing the game and reopening resets the FPS for the next recording.

I did notice Audacity writing its temporary files to the OS drive, so I tried without Audacity - no change. I've monitored the CPU, memory and disk I/O during recording - none of them hit anywhere near their max.

I realise I need to get new hardware and I'm hoping to over Christmas, however until then I'm trying to get this machine to work. Could anyone provide any suggestions to help me get a stable framerate?

If this is not the right place for such a question, please do point me to the right part of Stack Exchange or any external forums you think may help.

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If you are "limiting to 60" using vsync, then it sounds a lot like triple buffering and vsync plateaus. With vsync, the software must wait for a video "wait state" and if the time it takes to do {magic} is even slightly longer than it should be, it must wait for the next wait state and you go from (IIRC) 60 to 30 (then 15, then 7). Again, if I remember correctly, with triple buffering, the plateaus are 60, 45, 30, etc. One obvious potential bottleneck is constant virus scanning of progressively larger files (audacity, video temp files) –  horatio Nov 29 '12 at 17:14
    
Sorry horatio, I should have mentioned that I've actually disabled Triple Buffering and set vsync to "adaptive" after reading up about how vsync can cause frame lag. I've also disabled my virus scanner while trying to record and monitored open files - no luck :( –  Andrew White Nov 30 '12 at 10:57
    
One thing I've noticed is that the FPS overlay on the main Minecraft menu screen seems to sit at "36" when not recording. It used to sit in the hundreds. The timing correlates to my recording slowing down. –  Andrew White Nov 30 '12 at 11:26
    
What happens when you disable "adaptive"? –  horatio Nov 30 '12 at 14:54
    
also what revision of the game? –  horatio Nov 30 '12 at 14:57
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1 Answer 1

You are hitting a bottleneck of some kind - from your description it is hard to see whether it is CPU or I/O based, but things that could well be culprits:

  • You are only running with 3GB of RAM - this is pretty low. The Java engine can require large amounts of RAM. I play a fair bit of Minecraft and 8GB really helped me out!
  • A Core 2 Duo is not exactly cutting edge - get a nice fast Quad Core i7 CPU if you want a gaming machine.

Until you upgrade, the following may help:

  • Your drives should be on separate controllers, otherwise they will have to share the bandwidth.
  • Reduce screen resolution and graphics depth/quality
  • Shut down all other applications (including background apps)
share|improve this answer
    
Hey Dr Mayhem, thanks for your answer, Whilst I do understand my machine is fairly low spec, I haven't CPU, RAM or disk IO being anywhere near maximum. I was also under the impression that Minecraft ran better with less memory allocated, as indicated by the creator of Optifine. I might go try it with more RAM allocated later tonight. The controller idea is awesome, I'll open her up and give that a try! Unfortunately I've already tried your other suggestions :(. Thanks! –  Andrew White Nov 30 '12 at 11:00
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