NVIDIA NeMo RL uses FP8 to speed Qwen3-8B training by 1.48x

What the tweet revealed

NVIDIA AI posted that NeMo RL “supports FP8 to speed up RL workloads” by 1.48x on Qwen3-8B-Base. The timestamp is unusually tight but valid: FxTwitter reports the tweet at 2026-04-22T21:00:02Z, two seconds before the supplied TODAY=2026-04-22T21:00:04Z.

The NVIDIA AI account usually posts applied AI infrastructure, NeMo, robotics, and model-optimization work. The linked NVIDIA Technical Blog gives the substance behind the short tweet. It focuses on reinforcement learning for reasoning-grade models, especially workflows using Group Relative Policy Optimization where generation and training phases create different throughput bottlenecks.

What the FP8 result means

The blog says NeMo RL is an open-source library within NVIDIA NeMo and describes an end-to-end FP8 recipe for RL. For linear layers, NVIDIA uses block-wise FP8 quantization inspired by the DeepSeek-V3 technical report. The post states that FP8 math has 2x peak throughput compared with BF16 math, while other modules can remain in BF16 where needed.

The Qwen3-8B-Base section is the key benchmark for this tweet. NVIDIA reports that applying FP8 to KV cache and attention yields an additional ~30% rollout-stage speedup over the linear W8A8 setup and an overall ~48% speedup compared with BF16. It also says token-level truncated importance sampling keeps validation accuracy aligned with the BF16 baseline, even though low precision can increase numerical mismatch.

This matters because agentic tool use and multi-step workflows make post-training loops more expensive. If FP8 recipes can preserve accuracy while increasing rollout throughput, teams can iterate on reward design, tool policies, and reasoning behaviors faster.

What to watch next is reproducibility outside NVIDIA’s stack: larger MoE models, longer responses, and non-NVIDIA serving engines will test whether the 1.48x claim becomes a general recipe or a tuned result for a specific pipeline. Source: NVIDIA AI source tweet · NVIDIA technical blog