Max dimension of cudaArray

[xaraca]

Is there a limit on the size of a single dimension of a cudaArray?

[mfatica]

Yes.

From the new FAQ:

What are the maximum texture sizes supported?

The maximum size for a 2D texture is 64K by 32K pixels. However there is a limitation in the current CUDA release that prevents you from allocating arrays this large.

1D textures are limited to 8K elements.

1D “buffer” textures bound to linear memory are limited to 2^27 elements.

The hardware only supports 1, 2 and 4-component textures, not 3-component textures.

[Morph208]

The maximum size for a 2D texture is 64K by 32K pixels. However there is a limitation in the current CUDA release that prevents you from allocating arrays this large.

I’ve just tried with the release 1.0. It seems like I can’t choose more than 4096 texels as width. I mean, I detect no error with cudaGetLastError(). But the texture fetching I’m doing using this array gives me anything consistent (weird numbers or nan). Here is the code:

#define WIDTH 4096

...

cudaChannelFormatDesc channelDesc = cudaCreateChannelDesc(32, 32, 32, 32, cudaChannelFormatKindFloat);

cudaMallocArray(&array, &channelDesc, WIDTH, Height);

cudaBindTextureToArray(array_ref, array);

If I choose a number greater than 4096 for MAXLENGTH, it doesn’t work properly. I don’t mind I can use 4096 of course. But I’m surprised because the limit is supposed to be 64K.

(N.B.: Height is low, few units)

[Morph208]

Actually the problem seems more tricky. The more I add texels in my textures (by increasing the model size) the more I need to decrease WIDTH… I’m using about 15 textures. Would it be possible that there is some mess somewhere with the allocation in global memory?