Hmm, I think you might have to adjust the padding to be 128 bits then: __shared__ float As[(CHUNKSIZE+4) \* CHUNKSIZE] Ultimately it's down to trial and e

Hmm, I think you might have to adjust the padding to be 128 bits then: __shared__ float As[(CHUNKSIZE+4) \* CHUNKSIZE] Ultimately it's down to trial and error, like always with GPGPU.