What will happen when shaders meet textures?

Graphics and GPU Programming Programming

Started by BlueWanderer April 24, 2012 06:29 PM

2 comments, last by BlueWanderer 11 years, 11 months ago

122

Author

April 24, 2012 06:29 PM

As it seems to me, when there are around one thousand shader units, we can only expect around one hundred or less texture units. So when the shaders are sampling textures, will they be stalled?

MJP

20,295

April 24, 2012 06:57 PM

In general, the thread with the texture fetch will stall while it waits for the fetch to complete. However a GPU will keep many many threads in flight simultaneously, and will typically have another warp/wavefront of threads that it can swap out so that execution can continue. Read through this for more details.

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Hornsj3

195

April 24, 2012 09:37 PM

I would have answered "total particle reversal", but your answer seems correct too.

BlueWanderer

122

Author

April 25, 2012 03:58 AM

Let's put it another way. My card has 16 x 9 SIMD units and 4 x 9 texture mapping units (and I wonder if the 2 "x 9"s have same meaning). Can I say that one SIMD group have 4 texture mapping units? If so, when the group is executing one sampling instruction, how the texture mapping units are used? If not, how will they do the job?