I have a question regarding the L1 Cache on Maxwell GPUs, specifically the GTX 840M.
The Maxwell Tuning Guide (https://docs.nvidia.com/cuda/maxwell-tuning-guide/index.html) says:
As with Kepler, global loads in Maxwell are cached in L2 only…
Local loads also are cached in L2 only…
So the GPU does not cache local or global loads. What is the L1 cache used for, then?
Since it is unified with the texture cache it is probably used for textures. The Tuning Guide also states:
As with Kepler, global loads in Maxwell are cached in L2 only, unless using the LDG read-only data cache mechanism introduced in Kepler.
So the cache can apparently also hold read-only data using the LDG mechanism. Is there any other usage for the L1 Cache? I know, there exists this opt-in mechanism to enable global loads, but I think, this is not supported for Nvidia GM108, right? Is there anything else?