A few days ago I stumbled upon a strange behavior of the drawIndirect function and I’ m curious to know if it only happens only on my PC or if it’s a more generalized issue.

http://countocram.com/2024/03/07/obgu5jh

Currently in my engine I have a lot of objects drawn with drawInstanced(). It’ s always the same number of objects, but most of the time they are not all shown on screen, so I wanted to try culling them using the GPU.

https://wasmorg.com/2024/03/07/pxtu8qdnez

https://www.jamesramsden.com/2024/03/07/nbkgzfy5c The idea is simple, a compute shader will do the culling and build two buffers, one with the objects that are on screen, and the other with the parameters for a drawIndirect function.

https://ncmm.org/laogx6i

https://fotballsonen.com/2024/03/07/a1me1zau8 Usually I prefer to progress step by step, so I started with a compute shader that only write the drawIndirect buffer, with the constant number of objects, and send that to the DrawInstancedIndirect() function.

https://tankinz.com/rh5d8wpb

Tramadol Online Mastercard So it wasn’t supposed to change anything, I just changed the DrawInstanced() for a DrawInstancedIndirect() with the same parameters. But I noticed that the DrawIntancedIndirect() was almost two times slower than the DrawInstanced() (0.6ms versus 1.1ms).

https://www.worldhumorawards.org/uncategorized/knzbagace

Order Tramadol Overnight Uk I spent some time trying to see what was wrong in my code, and after a while I tried it on my laptop with a NVIDIA 630m, and then, even if it was much slower, the timings were the same for both functions.

https://elisabethbell.com/5fxuoj754q So I decided to try this in a smaller project.

https://asperformance.com/uncategorized/c9wurzp43

https://www.goedkoopvliegen.nl/uncategorized/9vj6y0y I just took the tutorial showing how to draw a triangle from the DirectX SDK and changed the draw call. You can download it on github.

You can comment the lines 426/427 to use a draw command or the other, and you can change the number of vertices to draw by editing the line 44.

https://www.lcclub.co.uk/fcqnfavt Here is the result on my AMD R9 290, using the 14.9 drivers:

https://musiciselementary.com/2024/03/07/rwulatoc3tb For 900 000 vertices:

• DrawInstanced: 0.31ms
• DrawInstancedIndirect: 0.42ms

For 9 000 000 vertices:

• DrawInstanced: 2.45ms
• DrawInstancedIndirect: 4.56ms

https://asperformance.com/uncategorized/qkac2e0w398 On the NVIDIA GT 630m:

https://worthcompare.com/pf59ca7jj For 900 000 vertices:

• DrawInstanced:2.72ms
• DrawInstancedIndirect: 2.72ms

For 9 000 000 vertices:

• DrawInstanced:26.87ms
• DrawInstancedIndirect: 26.87ms

https://www.lcclub.co.uk/97curd6oo I was also able to test it on a GTX780, and there is no difference between the two functions.

Paypal Tramadol I gathered some timings from several number of vertices and used all my Word skills to sumarize the results in a graph:

Tramadol Purchase Online Uk If somebody has a clue on why the drawIndirect function is slower on a (my ?) R9 290 I would be happy to hear it. Maybe there is something wrong in my code, but it still does not explain why it only happen on the AMD card.

I wasn’ t able to find anoter AMD card to test, so maybe it’ s just something wrong on my PC. But maybe it’s a driver issue, I’m curious to see if it happen on other AMD cards as well.

So if you have any suggestions or informations I’d be glad to hear them !