Why FPS for my integrated video cards (SiS) is lower than 60?

Why FPS for my integrated video cards (SiS) is lower than 60?
Monitor refresh rate is 85 Hz
This was measured without any drawing - just swapping buffers (specifying glSwapHintRectWIN - doesn’t help, but for PCI Cirrus Logic - that was a key!)

Most likely because you’re not getting OpenGL acceleration, just like in your previous thread.

Basic questions like these should really go in the beginners forum, okay?

– Tom

That is not necessarily true. I also have
Sis chip on my laptop and get no more than
55-60 fps when rendering 2-4 polygons.
I get acceleration.

You can check if your getting HW acceleration,
check the GL_VENDOR, glGetString. If it says Microsoft, then software accel, otherwise it is hardware accel. Also, the implementation of opengl is not very good on Sis chips. Several opengl calls for state change do not work when they should.

You could also try an infinite loop for your drawing code, this will remove the slow down
due to system message handling. Better yet, you can put your rendering code in a seperate thread and then set the refresh as high as you want and the message loop will not be a problem.

I have hardware acceleration!
I want optimize my program and get better performance of FPS but not in cost of cpu time.

And you are right that SiS’ opengl implementation can’t change states correctly.

Okay, I have to admit that I’m not too familiar with SiS’ graphics offerings. Which chipset specifically are we talking about here? Whatever it is, it couldn’t possibly be widespread enough to be worth worrying about, could it?

– Tom

Actually since my application is mainly developed on my laptop and tested on several other comps, I often find myself unsure whether I missed something, or Sis driver has a problem.

What main cycle do you use? I saw that problem when my pupils used system timer. You know, system timer is very unprecise. It cannot generate ticks smaller than 20ms (on certain computers even bigger). I have S3 Savage8 card - even worse that yours and I allways get at least 2000 fps even with some polygons rendered. Try to make for loop of rendering and measure time it takes.

I may be wrong here, but isn’t 85Hz one of those well-known interlaced frequencies?

I’m certainly no expert on GL cards, but if we’re talking about an interlaced frequency, you might be getting half of that frequency when VSync is on, so 43 FPS?

Originally posted by T101:
I may be wrong here, but isn’t 85Hz one of those well-known interlaced frequencies?

you are wrong. never heard about an 85hz interlaced monitor mode… usually interlacing was used with 60h.

Not 60Hz. 87Hz (so yes I’m probably wrong because this is 85Hz). T101 regrets the error…
But unless it’s a slow (non-CRT) display, interlaced modes flicker, so it should be pretty obvious.