How many registers could one thread use at most? When would the data be spit out to local memory?

[Hardy616]

The nvcc 3.0 documentation says 128 registers per thread (pp 16-17). I have in in my head that the limit is lower for Fermi, but I can’t remember where it is documented.

Thanks so much. I thought this 128 was the maximum only for this --maxrregcount instruction. So 128 registers per thread is also for hardware.

[Jimmy_Pettersson]

So this means if I use 64 threads in one block, then I can use at most 127*64=8128 registers which means the other 8k registers are wasted?

Nope, not wasted. You will be able to have another active block.

[Jimmy_Pettersson]

So this means if I use 64 threads in one block, then I can use at most 127*64=8128 registers which means the other 8k registers are wasted?

Nope, not wasted. You will be able to have another active block.