Rendering: uses processor or vid card more?

[Beller0ph1]

Simple question hopefully. I have a friend who's brother is doing some OpenGL rendering. What part of the hardware does the renderer use the most, the processor, or the video card? He's building a system and wants to keep the cost around 700. Any ideas?

 

[einsatz]

Depdends but for OpenGL the drivers usually shove stuff to the GPU as much as it can. CPU does other things. For example, the CPU may be working on geometry while the GPU works on texturing. Or CPU can be working on particle physics while the GPU handles dynamic lighting.

 

[VIAN]

GPU. GPU renders all that you see. CPU calculates physics and AI and some other stuff.

OpenGL also supports CPU graphical extensions such as 3D Now!, SSE2. I don't really know what they do, but the important thing you need to know is that the GPU is used more.

 

[Beller0ph1]

Thanks for the replies!

 

[BFG10K]

For professional 3D packages the bottleneck tends to be firmly with the GPU.

For games it varies but most of them these days are both CPU and GPU limited.

 

[BenSkywalker]

Depends on which 'rendering' you are talking about. I assume you mean some type of vizualization application, if that is the case while you are working with a model/scene the GPU is the bottleneck, when you handle your final render the processor is the limiting factor. Both of those are both rendering, but the demands flip around completely depending on what you are doing.

Which app will he be using?

 

[Beller0ph1]

I'm not sure which app he's using, but I think my friend was talking about doing the final render. Like designing something, then letting the program churn out the final product. Next time I see him I'll ask. Thanks for all the responses so far though!

 

[skurk]

Hey, I'm the friend. The application is Form Z for architecural renderings. From the posts I understand that the GPU (video card) handles onscreen manipulation of models and whatnot, but when finally rendeing the CPU is mostly used which is as I thought. Am I right? Thanks a lot for the help.

 

[Viper96720]

Processor read somewhere that Form Z is based on lightworks rendering engine which used processor most.

 

[lifeguard1999]

FormZ is a 3D modeling program. When you are doing the modeling, the GPU is doing the majority of the work. When you do the final rendering (using form·Z RenderZone which is the version of form·Z that includes photorealistic rendering) the CPU is the bottleneck.

 

[BenSkywalker]

From the posts I understand that the GPU (video card) handles onscreen manipulation of models and whatnot, but when finally rendeing the CPU is mostly used which is as I thought. Am I right?

Correct. Does FormZ use a Lightworks based render engine(it is a fairly popular render engine in terms of licenses)? If so, are you using radiosity? No matter what processor you get, radiosity absolutely kills it(I worked with Lightworks renderers for a few years). IME I held off on final rendering until I was leaving my rig for eight hours or more. No gripes at all with the final results mind you, and limiting it to RayTracing it was quite quick(although didn't look nearly as good), but nothing you buy is going to be too fast(although you are likely well aware of that ).