Look Ma, No Bubbles Designing a Low-Latency Megakernel for Llama-1B
a year ago
- #GPU
- #LLM
- #Performance
- Designing a low-latency megakernel for Llama-1B to improve LLM inference speed.
- Existing systems like vLLM and SGLang use only 50% of GPU bandwidth due to kernel overheads.
- The megakernel approach fuses the entire forward pass into a single kernel, reducing stalls and improving performance.
- Key challenges addressed: fusing operations, sharing shared memory, and synchronization within the megakernel.
- Performance results: 1.5x faster than SGLang and 2.5x faster than vLLM on an H100.
- Future potential for megakernels to accelerate a broader set of AI workloads.