From CRT to LCD

[James Gray]

On 16/09/2006, at 10:30 AM, dethadol wrote:

> <snip>
>>> Thanks that is brilliant. Is there any reason for using 3d
>>> hardware-accelerated even if I don't use it please?
>>
>> games, video playing, video rendering CAD design and other
>> graphics intensive operations all benefit from 3D acceleration.
>> If you use these kind of applications, then try the closed
>> source drivers and see if the benefit is worth it.
> </snip>
>
> Sorry to show my ignorance but can anyone explain why 3D accel is  
> needed
> for video playing please?

Generally speaking, it isn't.  However, many video cards with 3D  
accelleration are also capable of off-loading much of the video- 
decoding from the CPU as well.  This will allow your system to remain  
responsive while you play back gitter and stutter free video.   
Without the decode off-load (using 3D accelerated video cards) your  
poor CPU has to do all the work.  Given that modern CPU's are quite  
powerful you probably wouldn't have any problems without the OpenGL  
acceleration, but why waste CPU time on something like video when  
your graphics card spends most of its life idling in the background?

Multi-core CPU's are even more adept at handling multiple tasks (such  
as video decode and "other" stuff at the same time)...but why not  
utilise a resource that will provide you with some significant  
performance benefits?  FWIW, I've noticed that enabling OpenGL  
options on video play back generally results in better images and  
smoother play back (at least in mplayer anyway).  YMMV.

Cheers,

James