GPU × use-case guide · Reasoning / agentic

Is the A100 40GB PCIe a good GPU for reasoning / agentic?

The A100 40GB PCIe is a ampere NVIDIA GPU with 40 GB HBM2e (1555 GB/s), 312 TFLOPS BF16 / 312 TFLOPS FP8, and a 250 W TDP. Reasoning / agentic workloads care most about long output generations (chain-of-thought), so decode throughput and KV-cache headroom dominate. Here's how the A100 40GB PCIe measures up.

What models fit on a single A100 40GB PCIe?

Weights only, reserving ~25% of the 40 GB for KV cache, activations and fragmentation. ✓ = fits on one card.

Largest single-card fit: Qwen 2.5 14B at BF16, Gemma 2 27B at FP8, Mixtral 8x7B (MoE) at INT4. Bigger models need tensor-parallel across 8 cards.

A100 40GB PCIe for reasoning / agentic, specifically

Reasoning / agentic is context-heavy, so the KV cache — not the weights — is what fills the 40 GB. On the A100 40GB PCIe you'll trade context length against batch size: long prompts mean fewer concurrent requests. Because it's latency-sensitive, run it at low batch sizes on a fast framework (vLLM ≈ 85% MFU) rather than maximising batch. Size it precisely on the calculator.

A100 40GB PCIe pricing across providers

Verdict

At 40 GB, the A100 40GB PCIe is a solid mid-to-high-tier choice for reasoning / agentic: single-card up to Qwen 2.5 14B (BF16) or Gemma 2 27B (FP8), and cost-effective at ~$0.99/hr.