Slick Forums

I created a blank BasicGame with nothing in the update or render methods and set vsync to true. The CPU usage is very high (over 50% of my dual core). The fps is steady at 60 and I have a black window displayed. Shouldn't the vsync cause Slick to sleep or is it just doing a busy loop in the background?

Also try using GameContainer.setTargetFrameRate, as that will cause the actual sleeping via Display.sync.

Ok, with VSync and setTargetFrameRate(60) both set it was still gobbling up my cpu. I tried with just setTargetFrameRate(60) and it was down to 1 or 2% which is great.

More testing on my real game trying with just setTargetFrameRate(60) and I get screen tearing. VSync obviously solves it but why does it cause so much cpu usage compared to setTargetFrameRate(60)? Looking for advice on how can I eliminate screen tear without spiking my cpu.

High CPU usage with vsync is an indication for a bad/not correctly working GL driver which does busy looping instead of using interrupts.

_________________
TWL - The Themable Widget Library

Hmm. I'm running Windows XP 32 bit, Geforce 8800 GT with the latest driver. So it's a problem with this video driver?

If anybody else runs into this with their nvidia cards I found a solution after a bit of googling. In a nutshell, from the NVidia Control Panel go to Manage 3D Settings/Global Settings and set the "Threaded Optimization" property to false. Once I did this, my cpu went from spiked to 1 or 2% usage. Needless to say, I'm not impressed with "Threaded Optimization".

http://www.retrocopy.com/blog/29/nvidia ... moron.aspx