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View Full Version : Calculating expected FPS?



omdown
03-26-2010, 11:19 AM
I'm curious.. I know this is obviously dependent on a LOT of variables, but are there any ways to ballpark expected FPS for a scene with a given number of verticies? I'm working on a project with a small sample scene with ~250K verticies, plus normals, colors, etc., stored in two VBOs (four objects, one of one type w/~90K verts, and three of the other w/~50K), running through a Quadro FX 4500. At present, we're only managing about 25fps. Given how complex the scene is, that doesn't strike me as necessarily surprising, but others seem to disagree, so I could be wrong. Any thoughts?

zeoverlord
03-26-2010, 01:21 PM
the number of vertics are very much dependent on fillrate, so hundreds of large polygons can take as long as tens of thousands of smaller ones.
You also have to add to that what kind of shading/texturing/blending your doing, if any.

So it's really hard to say.

omdown
03-26-2010, 01:42 PM
Yeah that's what I expected. I don't really know the size of the polys. Well, I know the one with 90ishK is composed of pretty large ones (extremely large object) while the ones of 50ishK are likely pretty small since they're MUCH smaller than the large object but still have a ton of verts. No blending or texturing, but we are doing some shading that has a couple of function calls. I'm not a GLSL expert but I'm told it's not anything that intense.

ZbuffeR
03-26-2010, 01:54 PM
Try the same rendering but on a very tiny window to rule out shading bottleneck.

omdown
03-29-2010, 06:01 AM
Try the same rendering but on a very tiny window to rule out shading bottleneck.

Shading bottleneck? You mean the shader bogging it down? Shouldn't it be faster in a smaller window regardless (less to render to the final output)?

ZbuffeR
03-29-2010, 06:50 AM
Less fragments to render, but still as many vertices to process. So it allows to eliminate 1 potential bottleneck, to check for the other.