General OpenGL programming question

[CAM]

Ok,

Suppose I take some basic openGL code that compiles and runs. I run the code on a PC with a basic video card, and then change the card to a super fast video card. I'm assuming that the code will run a lot faster, correct? I say this, because I've picked up some code that I need to maintain and it's written in OpenGL, the thing is that the code is running on a superfast PC with a top end ASUS video card, and the CPU at times when displaying video is 100% flat out. I'm assuming here it isn't using the GPU on the card? Or will it automatically use the GPU when the drivers have been installed?

Many thanks in advance.

[mogumbo]

The driver will decide when to use the CPU and when to use the GPU. If graphics aren't accelerated by the GPU you'll know it because you'll have a really poor framerate. That's when it is time to install a new driver.

You know, every opengl app I've ever written in Windows pegs the CPU. I always figured it was just because Windows sucks, but there's probably a more scientific reason for it.

[marcus256]

You may still get 100% CPU usage (it's actually the most probable sceanrio, unless the code is manually stalled with some sort of wait/delay). The CPU and the GPU are working in parallell, and in a decently well balanced system both the CPU and the GPU will be working at 100%.

[Deiussum]

If you are updating your display as quickly as possible, which is what you usually should be doing if you have animations, the CPU will generally be at or near 100% due to the continuous processing of WM_PAINT messages.

[CAM]

Thanks for all the info, it's starting to make sense now. I figured that the CPU wouldn't should be at 100% because the GPU would be doing the work!

Thanks again!