[ltp] glxgears on a T42 (Fedora Core 3) with ATI Mobility Radon 7500

[David A. Desrosiers]

> BTW, on an old Thinkpad 600X running Fedora Core 3, etc., this 
> phenomena does not occur.  Moreover, the gears visually turn very 
> fast even though the frame rate is about 100 fps.

	What you're seeing visually is the same effect that spinning 
rims on a car at certain speeds will exhibit.. it will almost look as 
though the wheels are spinning backwards slowly, or rotating much 
slower forwards than is actually happening.

	The gears are spinning fast, but they appear to be moving 
slowly on your screen because it executes a full rotation before the 
screen refreshes to show it.

	When you cover the glxgears window partially with a terminal 
window, you're simply "shunting" some of that drawing output, so what 
remains can rotate faster. Its the same thing if you resize that 
window to be smaller or larger.

	Its doing exactly what it should be doing. 

	One thing you can try is backing the bpp down to 16, and using 
the proper ATI or X.org 3D/GL drivers for your r300 chipset, instead 
of the built-in driver that Fedora provides. You should see a pretty 
big improvement if you do, but you'll lose suspend and some other key 
things if you go that route, last I heard.

	I don't personally use games, so I don't need GL. You might. 
	

David A. Desrosiers
desrod@gnu-designs.com
http://gnu-designs.com