OpenGL on Windows (high CPU usage)

Yeah, at the moment we DO tell users to avoid those plugins. There’s no other solution.

I was just hoping to understand why OpenGL is so inefficient when it can’t use hardware acceleration (obviously, I’d expect it to be inefficient - but nowhere near as bad as it actually is…)

[QUOTE=johne53;1293495]
I was just hoping to understand why OpenGL is so inefficient when it can’t use hardware acceleration (obviously, I’d expect it to be inefficient - but nowhere near as bad as it actually is…)[/QUOTE]

By the above, are you saying that you now know that the cases where you see poor performance are cases where GPU acceleration is not being used? Before you were just suspecting this. If so, then of course it’s going to be inefficient. CPUs weren’t built for that.

You (or the plugin authors) can probably test for this case by creating a GL context and querying the values of GL_RENDERER and GL_VERSION. If you/they see “GDI Generic” or OpenGL version “1.1.0”, then you know what’s going on: they’re doing something to force Microsoft’s old CPU software renderer, which is going to be slow. This could indicate that the GPU drivers have not been installed or installed properly, or that the plugins (or your app) are doing something to force use of Microsoft’s software renderer over the installed GPU’s hardware-accelerated graphics driver.

Correct me if I’m wrong, but you/we still don’t know what’s going on here yet that makes those particular plugin’s GUI windows so inefficient. The solution may be to get your plugin authors to test their code more widely before publishing it. Alternatively, do some profiling with a plugin that exhibits the problem and see what it’s doing (e.g. run VerySleepy on it). Where’s it spending all of its time?

As to those GUI windows, what API(s) are being used to render them? If GDI, from what I’ve read mixing GDI with OpenGL on Vista+ will force a fallback to Microsoft’s software (CPU) OpenGL implementation, which will be slow. A few old pages on this: link, link, link, link.

Those are just a few ideas you might explore if you’re interested in getting to the root of the problem.

Thanks, Dark Photon - I’ll contact the plugin manufacturers and let them know about the VerySleepy app. Hopefully that’ll move things forward.

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