Re: [Chromium-users] About frame rate of Chromium

[Randall F. <ran...@co...>]

Hello,
 You are asking the fundamental scalable rendering question.
While Chromium makes it possible to distribute your rendering
load over many machines, it does not in general "just make
rendering faster", there are a lot of variables.  What makes
parallel rendering faster? distributing the load.  So, what
kind of load does your application have?  Can it be independently
subdivided into smaller pieces (e.g. no global transparency
sorting issues)?  Are you looking to scale the rendering performance
or the size of the display (many people use Cr just to scale the
display)?  How dynamic is your geometry vs how much bandwidth
do you have in your cluster?  Finally, are you looking for hard
or soft scaling?  Hard scaling is where you want to throw more
hardware at something and make it go faster.  Soft scaling is
where you increase the data load and the hardware resources,
but keep the performance the same.  The former can be very
hard for a number of reasons, while the latter is generally
achievable.

 Let me make some assumptions and give you some advice.  First,
I assume you have a large dataset with rendering that does not
require any global sorting or multi-pass techniques to draw.
Second, I assume your goal is to speed up rendering to a single
display, not a tiled powerwall. Third, I assume that your dataset
is generally static.  If these are correct, you should look at
Chromium sort last rendering.  My suggesting, write a parallel
version of your application (consider using CRUT) and use the
Cr parallel OpenGL API to render sub-chunks of the model on
multiple nodes, letting Chromium composite the resulting framelets
into a final image.  Note: there is some overhead for this, that
is there is a maxium framerate given the overall data
manipulation Chromium requires, but that is generally a flat
overhead wrt the size of the dataset.  Of course if any of
my assumptions are incorrect, another approach is needed.

Hope it helps...

wangshuai wrote:
> Hello Brian Paul！
>  	
> 	Well,then how can I get more performance with Chromium? 
> 	What SPU or configuration of cluster can I use with Chromium?
> 	
> 	My programme is very slower on my computer because of huge model data and much particle system.
> 	I think cluster rendering can make my programme faster,then I choose Chromium.
> 	Howerver, the result isn't as I desired.
> 	Am I wrong?  Could you give me some advice?
> 	
> 	Thanks for replying!
> 
> ======= Brian Paul wrote：=======
> 
> 
>>wangshuai wrote:
>>
>>>Chromium-users，Helleo！
>>>		
>>>	I am a new user of Chromium.
>>>	And I build a cluster with 3 node(one is client,others are servers) and 100M Ethernet. 
>>>	
>>>	I run "city" without Chromium and the frame rate is 80.
>>>	Howerver,when I run "city" on Chromium with "simplemural.conf", the frame rate is only 50.
>>>	
>>>	Can anyone tell me some test results about yours?
>>
>>Well, certainly the program is going to run a bit slower with the
>>tilesort SPU since the SPU itself takes some CPU time and the drawing
>>commands have to be sent over the network.
>>
>>-Brian
>>.
> 
> 
> = = = = = = = = = = = = = = = = = = = =
> 			
> 
> Best regards!
>  
> 				 
> 　　　　　　　　wangshuai
> 　　　　　　　　ws...@ho...
> 　　　　　　　　　　2004-06-26
> 
> NS^甸[)([ZrA诖)+)啖ZrHZ凳&
> +?谦)+-
> +?谦(悍~zw玷咤l?)撸!⒑kers=


-- 
rjf.
Randy Frank                            | ASCI Visualization
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