A100 SXM4 40GB vs B300 SXM6

AmperevsBlackwell UltraUpdated 35 days ago

The B300 SXM6 emerges as the superior choice for dominant AI workloads like LLM training and inference: its 2250 TFLOPS FP16 dwarfs A100's 312 TFLOPS, and 288 GB VRAM crushes 40 GB limitations. Bandwidth at 12000 GB/s versus 2039 GB/s ensures scalability. While pricier at average $6.44 per hour, performance gains justify investment for most users.

A100 SXM4 40GB from $0.73/hrB300 SXM6 from $7.39/hr

Specifications Compared

SpecA100B300
TDP400W1200W
VRAM40-80 GB288 GB
CUDA Cores6,912
Memory TypeHBM2eHBM3e
ArchitectureAmpereBlackwell Ultra
Form FactorsSXM4, PCIeSXM
InterconnectNVLink, PCIe 4.0, InfiniBandNVSwitch, NVLink
Tensor Cores432
FP16 Performance312 TFLOPS2,250 TFLOPS
FP32 Performance19.5 TFLOPS90 TFLOPS
FP64 Performance9.7 TFLOPS45 TFLOPS
INT8 Performance624 TOPS4,500 TOPS
Memory Bandwidth2,039 GB/s12,000 GB/s

Performance Analysis

The FP16 performance gap is substantial: A100 delivers 312 TFLOPS, but B300 provides 2250 TFLOPS, enabling seven times faster matrix operations critical for deep learning training. FP32 throughput rises from 19.5 TFLOPS to 90 TFLOPS, benefiting scientific simulations and precision inference. In real-world terms, this accelerates training cycles for large language models, reducing time from days to hours on equivalent datasets.

Memory bandwidth profoundly impacts workloads: A100's 2039 GB/s supports moderate batch sizes, whereas B300's 12000 GB/s nearly sixfold increase minimizes data bottlenecks during inference. Combined with 288 GB versus 40 GB VRAM, B300 handles enormous models or batches without swapping, ideal for trillion-parameter LLMs. FP8 at 4500 TFLOPS further optimizes low-precision inference, slashing latency in deployment scenarios.

Training benefits most from B300's specs, as higher FP16 and VRAM sustain longer sequences without out-of-memory errors. Inference gains from bandwidth allow real-time serving at scale, while A100 suffices for legacy or smaller-scale applications.

Live Cloud Pricing

Real-time prices from 25+ providers. Updated every 60 seconds.

A100 SXM4 40GB

ProviderGPU ModelVRAMHost SpecsRegionPriceStatusAction
Vast.ai
Vast.ai
NVIDIA A100 SXM4 80GB
80GB VRAM
$0.73/GPU/hr
Available
LeaderGPU
LeaderGPU
8×NVIDIA A100 PCIe 80GB
80GB VRAM
$0.90/GPU/hr
$7.20/hr total (8×)
Available
Vast.ai
Vast.ai
2×NVIDIA A100 SXM4 80GB
80GB VRAM
$1.00/GPU/hr
$2.00/hr total (2×)
Available
Denvr
Denvr
4×NVIDIA A100 PCIe 80GB
80GB VRAM
$1.15/GPU/hr
$4.60/hr total (4×)
Denvr
Denvr
8×NVIDIA A100 SXM4 80GB
80GB VRAM
$1.15/GPU/hr
$9.20/hr total (8×)

B300 SXM6

ProviderGPU ModelVRAMHost SpecsRegionPriceStatusAction
RunPod
RunPod
NVIDIA B300 SXM6
262GB VRAM
$7.39/GPU/hr
Scaleway
Scaleway
8×NVIDIA B300 SXM6
262GB VRAM
$8.73/GPU/hr
$69.84/hr total (8×)
Available

Compare real-time pricing across 25+ providers

When to Choose the A100 SXM4 40GB

The A100 SXM4 40GB excels in cost-sensitive environments: its pricing from $1.00 per hour suits prototyping, fine-tuning medium models up to 40 GB VRAM, or running on 400W power budgets. Legacy software optimized for Ampere architecture avoids Blackwell compatibility efforts, and PCIe 4.0 or InfiniBand interconnects integrate into existing clusters without NVSwitch upgrades. Choose A100 for scientific computing or Stable Diffusion where 312 TFLOPS FP16 meets needs without premium costs.

When to Choose the B300 SXM6

The B300 SXM6 dominates large-scale AI training: 288 GB HBM3e VRAM and 12000 GB/s bandwidth manage trillion-parameter models infeasible on A100's 40 GB. Its 2250 TFLOPS FP16 speeds convergence, while 4500 TFLOPS FP8 optimizes inference for production serving. Select B300 for cutting-edge LLM development or high-throughput inference despite $2.45 per hour starting price and 1200W TDP.

Use Cases

LLM Training
B300 SXM6

B300's 288 GB VRAM and 2250 TFLOPS FP16 handle massive models and large batches that exceed A100's 40 GB and 312 TFLOPS limits. This reduces training time significantly.

LLM Inference
B300 SXM6

B300's 4500 TFLOPS FP8 and 12000 GB/s bandwidth enable low-latency serving of huge models. A100 struggles with memory constraints on similar scales.

Fine-tuning
Either

A100 suffices for models fitting 40 GB VRAM at $1.00 per hour starting price. B300 accelerates larger fine-tunes with 288 GB but at higher cost.

Stable Diffusion
B300 SXM6

B300's superior FP16 at 2250 TFLOPS and bandwidth generate images faster with bigger batches. A100 works for basic use but bottlenecks on high-res.

Scientific Computing
A100 SXM4 40GB

A100's 19.5 TFLOPS FP32 and lower 400W TDP fit precision simulations economically. B300's power and cost suit only extreme scales.

Frequently Asked Questions

What is the VRAM capacity of NVIDIA A100 SXM4 40GB versus B300 SXM6?

The A100 SXM4 40GB has 40 GB HBM2e VRAM. The B300 SXM6 provides 288 GB HBM3e VRAM. This difference allows B300 to load much larger models without fragmentation.

How do cloud prices compare for these GPUs?

A100 SXM4 40GB starts at $1.00 per hour with average $2.63 across five offers. B300 SXM6 begins at $2.45 per hour averaging $6.44 across seven offers. A100 offers better value for entry-level tasks.

Which GPU has higher FP16 performance?

B300 SXM6 delivers 2250 TFLOPS FP16, over seven times A100's 312 TFLOPS. This boosts training speed for neural networks. FP8 at 4500 TFLOPS on B300 further aids inference.

What are the memory bandwidth specs?

A100 achieves 2039 GB/s bandwidth. B300 reaches 12000 GB/s, nearly six times higher. Higher bandwidth on B300 supports larger batch sizes in training.

What is the power consumption difference?

A100 SXM4 40GB has 400W TDP. B300 SXM6 requires 1200W TDP. Lower power on A100 eases cooling and energy costs in clusters.

Which is better for large model training?

B300 SXM6 excels with 288 GB VRAM and 2250 TFLOPS FP16. A100's 40 GB limits scale for big LLMs. B300 cuts training duration dramatically.

Which is cheaper to rent, the A100 or the B300?

Cloud rental prices for both the A100 and B300 vary by provider, configuration, and availability. This page shows live pricing from 25+ providers updated every 60 seconds. Scroll to the Live Cloud Pricing section to compare current rates.

How much VRAM does the A100 have compared to the B300?

The A100 has 40 to 80 GB of HBM2e memory. The B300 has 288 GB of HBM3e memory.

Can I find A100 and B300 GPUs available to rent right now?

Yes. This page shows real-time availability across 25+ cloud GPU providers. The Live Cloud Pricing section displays only in-stock offers with current pricing.

What is the main difference between the A100 and the B300?

The A100 uses the Ampere architecture (2020) while the B300 uses Blackwell Ultra (2025). The B300 delivers 7.2x the FP16 throughput and 5.9x the memory bandwidth of the A100.

A100 SXM4 40GB vs B300 SXM6: 80GB vs 288GB | GPUPerHour