Jump to content
  • Advertisement
Sign in to follow this  
Ninja_Mouse

XNA full screen slow

This topic is 3254 days old which is more than the 365 day threshold we allow for new replies. Please post a new topic.

If you intended to correct an error in the post then please contact us.

Recommended Posts

Hello! I'm having an issue in that the frame rate in my simple 2D game drops to 50 fps when I put it into full screen mode. It is fine when in a window at the same resolution as my desktop, but full screen it becomes noticeably slower. I've done two things recently: 1) Upgraded XNA from 3.0 to 3.1. 2) Upgraded my computer from AMD 3700, ATI x1900 to Intel E8500, ATI 4890. Could either of these affected my frame rate when full screen? Thanks, Farran

Share this post


Link to post
Share on other sites
Advertisement
its most likely that you have v-sync on because in full screen your frame rate should go up because your computer doesn't have to worry about drawing the OS
what fps are you getting when your program is windowed?

Share this post


Link to post
Share on other sites
I just want to check that I'm clear about my issue. In windowed mode it is running very smoothly at 60 fps. When I flip to full screen mode, it drops to about 50 fps. It also feels like it is choppy.

It used to be fine before I upgraded my computer and XNA. Any ideas?

Share this post


Link to post
Share on other sites
How are you measuring your framerate? Also, are you running in a fixed timestep?

Share this post


Link to post
Share on other sites
I apologise to the kind people who replied and then I haven't for so long!

I don't think my FPS counter is an issue, but to clarify, I measure a certain amount of time e.g. 0.5f seconds, and count each frame that has passed in that time. After the time is up I calculate the FPS. In any case, I can feel the game becoming much slower regardless of what is displayed on the FPS counter.

I am running in a fixed time step and the V-sync is on.

To make things even stranger, I have found something else that I can't explain that affects my frame rate. I have a particle engine that makes explosions. If I spam the key for explosions, causing choas all over the screen, the frame rate will eventually drop significantly. It drops much lower in full screen, just to note.

Now here is the weirdness! After the crazy effects have worn off, my frame rate will go up to the normal 60 FPS! I can feel it is how it should be, very responsive. And even stranger, sometimes after a little bit e.g. a minute, it goes back to crappy 52 FPS or so. What the hell is going on!

I tried removing the particle engine altogether, to make sure it wasn't that messing things up, but it didn't make any difference.

This really makes me think it might be a driver issue. Any information or speculation will be appreciated!

Thanks,
Farran (the confused)

Share this post


Link to post
Share on other sites
Did you do any GPU profiling? Are you GPU or CPU bound? Is it possible your framerate is lower simply because there's more pixels to draw in fullscreen? Or are you getting hit by memory leaks / frequent memory allocations ?

Share this post


Link to post
Share on other sites
I have not done any GPU profiling, mostly because I don't know how!

I'm not sure about your reference to CPU or GPU bound. Do you mean the method in which I count frames? I think my FPS counter increments the frame count with each call to Draw() from the engine.

I can't say I've measured memory leaks. I can tell you, with exactly the same canvas size when windowed as when full screen, that toggling to full screen makes the game noticably slower and unresponsive. I simply use the ToggleFullsceen() function to achieve full screen.

I'm not jumping from a small windowed resolution to a much larger full screen resolution, I have both resolutions set the same. I've tried with different resolutions, but they all have the same issue.

Share this post


Link to post
Share on other sites
Sign in to follow this  

  • Advertisement
×

Important Information

By using GameDev.net, you agree to our community Guidelines, Terms of Use, and Privacy Policy.

We are the game development community.

Whether you are an indie, hobbyist, AAA developer, or just trying to learn, GameDev.net is the place for you to learn, share, and connect with the games industry. Learn more About Us or sign up!

Sign me up!