Constant Cache

Accelerated Computing CUDA CUDA Programming and Performance
1

Hi,

I would like to know the Constant Memory cache size for the Pascal & Volta Architecture

More specifically we have been working on Tegra TX2 & P5000

I checked some documents. But I could not find the details.
Kindly share the details.

2

The logical constant space is 64KB.

With respect to the cache, the size and structure of the cache is unpublished (by NVIDIA) AFAIK. A reasonable expectation is that the logical constant space is delivered through a cache on the order of 8KB per SM.

[url]Clean Technology Innovations for Oil Sands and Heavy Oil Production - Acceleware Ltd.

3

So, can I assume there is no specialized physical space for the constant memory, it just a logical space residing in device RAM in the same way as the global memory?

4

Yes. They physical backing for the constant logical space is GPU DRAM memory. The constant memory system consists of this physical backing, plus a per-SM constant cache resource.

Unfortunately it seems that acceleware has relocated or removed the link I used previously.

The answer here from Greg Smith also refers to an 8KB “working set size”:

[url]gpgpu - Why is the constant memory size limited in CUDA? - Stack Overflow

5

Thanks a lot!