Bank Conflict Visualizer

Hardware config

Banks:
Bank size (bytes):

Problem config

BLOCK_M:
BLOCK_N:
Element size (bytes):
Access group height:
Access group width:

For BF16/FP16, element size is 2 bytes.

Visualization config

Cell size:

Swizzle function

Maps logical indices to physical indices.
You can access the following variables:

num_banks, bank_size, BLOCK_M, BLOCK_N, elem_size, group_height, group_width Here is an example of a more sophisticated swizzle function (you can copy-paste to the box below). function swizzle(m, n) { const elems_full_banks = (num_banks * bank_size) / elem_size; const rows_full_banks = Math.max(elems_full_banks / BLOCK_N, 1); const height_full_banks = elems_full_banks / group_width; const xor_pattern = Math.floor(m / rows_full_banks) % (height_full_banks / rows_full_banks); const new_n = n ^ (xor_pattern * group_width); return [m, new_n]; }

• The grid below shows physical layout.
• Cell color denotes bank ID.
• The number pair in each cell denote logical indices (m,n).
• When you hover over the grid, it shows the group of elements that will be accessed at the same time (access group height and width).
• Bank conflicts occur when there is any bank ID that needs to service more than bank size (i.e. 4 bytes, assuming natural alignment).