Skip to content

[FA4-FP8] on the B300. Low utilization of TC FMA XFU during inference. #2701

Description

@Romaosir

Has anyone been paying attention to this issue? Running FP8 on the B300, the NCU profiling results show very low utilization of TC FMA XFU. Are there any ways to increase these and thus improve TFLOPS?

Pipe BF16 B200 BF16 B300 FP8 B200 FP8 B300
Tensor 87.7% 99.9% 43.6% 55.2%
XU/SFU (exp) 71.9% 50.3% 71.6% 55.7%
FMA 20.0% 13.1% 20.6% 14.9%
ALU 31.2% 31.0% 36.3% 40.8%
Issue 49.2% 46.3% 52.0% 54.6%
SM busy 90.1% 98.3% 69.2% 60.4%
Occupancy 23.4% 23.4% 23.4% 23.4%

Metadata

Metadata

Assignees

No one assigned

    Labels

    No labels
    No labels

    Type

    No type

    Fields

    No fields configured for issues without a type.

    Projects

    No projects

    Milestone

    No milestone

    Relationships

    None yet

    Development

    No branches or pull requests

    Issue actions