Discussion Game has started running very slowly on certain machines...

[alecw]

Hi,

I targetted a build of my game for Ubuntu. It worked fine, but appeared to run very slowly as if the frame rate was right down. CPU load etc was low on Ubuntu, so I put it down to the config of the VM I was using and didn't give it much thought.

Then I deployed the game onto a physical Ubuntu box with the same result - very slow, compared to the Windows builds.

Now on one of my (Windows) development machines only, the same thing is happening - my game runs very very slowly where before it was fine.

If I run the exact same code on a different Windows machine it's fine.

I don't think the game is running slowly because of conditions on the machine it's running on - there is no high CPU or memory usage etc, and it's not competing with other software for resources.

Has anyone else experienced this? Is there anything I can do to try to troubleshoot?

Many thanks,
alec

 

[rwkay]

You do have a hardware OpenGL implementation running - it would need that to run fast.

This can be harder on Ubuntu to get right depending on the GPU manufacturer that you have.

Russell

 

[alecw]

Thanks Russell. My focus would be on the Ubuntu side if I'd not started seeing the exact same symptoms on Windows. I can compile the self same codebase on two different Windows platforms - one will be fine, and the other will be "slow" where it wasn't before.

Are there any intermediate build files anywhere I can delete? I'm trying to play spot-the-difference between the machine that's OK and the one that has become slow..

alec

 

[rwkay]

On Windows adjust the Sleep Margin (I would recommend a figure of at least 10, though some machines may need it to be higher) adjusting that generally will help with variations between machines.

Russell

 

[alecw]

I'll give that a go, but what I'm seeing is a game that was fine yesterday is now not-fine on one machine and still-fine on another. I think I'll try building a binary and running that, to rule out anything related to build artefacts or the dev environment or anything like that.

 

[rwkay]

if you do that then remember you can change the sleep margin on the command line to test out various values on the machine that is having issues

-sleepmargin <integer-value>

can be used with the runner.

That should help with localised testing

Russell

 

[alecw]

I think I have solved the mystery for my Windows PC at least...

The machine that had suddenly become slow was a laptop. You gave me a clue when you said:

>>"You do have a hardware OpenGL implementation running - it would need that to run fast."

The laptop was running on batteries - when I plug the power in, the game goes fast; when I take the power away it goes slow (the change is evident even whilst the game is running!). There must be a power setting in Windows somewhere that's taking things down a peg or two when I'm on battery.

Thanks for your help,
alec