Requesting clarification for Shared Memory Bank Conflicts and Shared memory access?

[rs277]

Robert will probably be along with a more complete reply, but here are a couple of things.

@tavivekuh

So, from what I have read from multiple resources, bank conflicts occur when multiple threads access different address location with in the same bank.

This needs amending to:
“bank conflicts occur when multiple threads in a given warp access different address location with in the same bank.”

@tavivekuh

So when the 16 bit data gets stored in shared memory, a memory bank of width 32 bits will be storing two data variable each of size 16 bits. Hence, it will lead to two threads accessing two different 16 bit data variable from two different addresses within the same 32 bit memory bank. This should lead to a two way bank conflict, since bank conflicts are defined as different threads accessing different address location with in the same bank.

Quoting from the "Best Practices Guide":

“On devices of compute capability 5.x or newer, each bank has a bandwidth of 32 bits every clock cycle, and successive 32-bit words are assigned to successive banks.”

So with two 16 bit elements packed into one 32bit bank and one element accessed from successive threads causes no conflict.