How to calculate the number of warps to hide latency

Accelerated Computing CUDA CUDA Programming and Performance
1

my gou is GM107(maxwell)
for examplem the menory latency is 400 cycles and how to calculate the number of warps need to hidew the latency?

2

64 warps * number of SMs

3

How to calculate the 64 warps, could you explain to me?
and 64 warps means 2048 threads? is it too much?

4

64 warps = 2048 threads

look up the cuda max threads per multiprocessor spec