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View Full Version : perfomance of glMultiDrawElementsEXT



DSA
12-10-2003, 11:38 PM
Hi!

It seems to be no much difference between
using glMultiDrawElementsEXT and
doing multiply calls of DrawElements.

For example i have 150 000 triangles.
I render this geometry by multiply chunks.
Each have 20 triangles.

By using many DrawElements i have about
24.5 mln tris per second.

With glMultiDrawElementsEXT i have about
25 mln tris per second.

By using multiply DrawElements and chunks in size , about 250 triangles i have about
32 mln tris per second.

Is there any reason to use glMultiDrawElementsEXT ?

I always thinks that with glMultiDrawElementsEXT no matter size of bath.

zeckensack
12-11-2003, 12:14 PM
I haven't seen any performance benefits either. I think it's a pure driver emulation thing atm.
It could be hardware accelerated some day. So if it doesn't hurt your overall design, it's probably not a bad idea to use it, even though it buys you nothing today.

Once hardware starts getting PPPs, this will become much more interesting.

DSA
12-11-2003, 09:51 PM
As i understand , for todays hardware its completly unuseful.

I hope that glMultiDrawElementsExt help me draw multiply separate strips of model without degenerate triangles. But ...
in practice model have 3000 polys and strip length vary between 10 - 20
triangles. Its' about ~100-200 render calls for each strip.

It is faster to draw model as one triangle list and one draw call.