B300 SXM6 vs RTX A4000

Blackwell UltravsAmpereUpdated 35 days ago

B300 emerges as the superior choice for dominant AI workloads like LLM training and inference: its 2250 TFLOPS FP16, 288 GB VRAM, and 12000 GB/s bandwidth deliver unmatched scalability despite higher $6.44 per hour costs. A4000 lags for modern demands but persists in legacy or low-scale scenarios.

B300 SXM6 from $7.39/hrRTX A4000 from $0.08/hr

Specifications Compared

SpecB300RTX-A4000
TDP1200W140W
VRAM288 GB16 GB
Memory TypeHBM3eGDDR6
ArchitectureBlackwell UltraAmpere
Form FactorsSXMPCIe
InterconnectNVSwitch, NVLink
FP8 Performance4,500 TFLOPS
FP16 Performance2,250 TFLOPS19.2 TFLOPS
FP32 Performance90 TFLOPS19.2 TFLOPS
FP64 Performance45 TFLOPS
INT8 Performance4,500 TOPS
Memory Bandwidth12,000 GB/s448 GB/s

Performance Analysis

B300's FP16 performance of 2250 TFLOPS dwarfs A4000's 19.2 TFLOPS by over 117 times: this excels in neural network training where half-precision accelerates convergence without accuracy loss. B300's FP32 at 90 TFLOPS remains 4.7 times faster than A4000's 19.2 TFLOPS, benefiting simulation workloads requiring full precision.

Memory capacity defines scalability: B300's 288 GB HBM3e supports models with hundreds of billions of parameters, avoiding out-of-memory errors common on A4000's 16 GB GDDR6. Bandwidth of 12000 GB/s on B300 versus 448 GB/s on A4000 enables batch sizes up to 27 times larger, slashing inference latency and training epochs.

Power draw reveals deployment contexts: B300's 1200W TDP demands rack-scale cooling with NVSwitch and NVLink, while A4000's 140W fits PCIe slots for edge computing.

Live Cloud Pricing

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

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

RTX A4000

ProviderGPU ModelVRAMHost SpecsRegionPriceStatusAction
TensorDock
TensorDock
NVIDIA RTX A4000
16GB VRAM
$0.08/GPU/hr
Available
Vast.ai
Vast.ai
8×NVIDIA RTX A4000
16GB VRAM
$0.15/GPU/hr
$1.17/hr total (8×)
Available
Hyperstack
Hyperstack
4×NVIDIA RTX A4000
16GB VRAM
$0.15/GPU/hr
$0.60/hr total (4×)
Available
Hyperstack
Hyperstack
2×NVIDIA RTX A4000
16GB VRAM
$0.15/GPU/hr
$0.30/hr total (2×)
Available
Hyperstack
Hyperstack
NVIDIA RTX A4000
16GB VRAM
$0.15/GPU/hr
Available

Compare real-time pricing across 25+ providers

When to Choose the B300 SXM6

Opt for B300 in large-scale LLM training or inference where 288 GB VRAM handles models exceeding 500 billion parameters without partitioning. Its 4500 TFLOPS FP8 performance and 12000 GB/s bandwidth support trillion-parameter deployments at $2.45 per hour starting price.

B300 suits hyperscale environments leveraging SXM form factor and NVLink for multi-GPU scaling in cloud instances averaging $6.44 per hour.

When to Choose the RTX A4000

Choose A4000 for budget-constrained prototyping or small-model fine-tuning, where 16 GB VRAM suffices at $0.08 per hour. Its 140W TDP and PCIe compatibility enable easy integration into workstations without specialized infrastructure.

A4000 excels in real-time visualization or moderate Stable Diffusion tasks, offering 19.2 TFLOPS FP16 at an average $0.37 per hour across abundant cloud options.

Use Cases

LLM Training
B300 SXM6

B300's 288 GB HBM3e VRAM and 2250 TFLOPS FP16 handle massive models without sharding. A4000's 16 GB limits it to tiny datasets.

LLM Inference
B300 SXM6

4500 TFLOPS FP8 on B300 supports high-throughput serving of large models. A4000's 19.2 TFLOPS FP16 restricts batch sizes severely.

Fine-tuning
Either

B300 accelerates large-model tuning with 12000 GB/s bandwidth; A4000 suffices for models under 7 billion parameters at $0.08 per hour.

Stable Diffusion
RTX A4000

A4000's 16 GB GDDR6 manages 512x512 image generation efficiently at low $0.37 per hour average. B300 overkills routine tasks.

Scientific Computing
RTX A4000

A4000's balanced 19.2 TFLOPS FP32/FP16 fits simulations on PCIe setups. B300's 1200W TDP complicates non-AI scientific clusters.

Frequently Asked Questions

What is the VRAM difference between B300 and RTX A4000?

B300 provides 288 GB HBM3e VRAM, enabling massive AI models. RTX A4000 offers 16 GB GDDR6, suitable for smaller workloads.

How do cloud prices compare for these GPUs?

B300 starts at $2.45 per hour, averaging $6.44 across 7 offers. RTX A4000 begins at $0.08 per hour, averaging $0.37 across 28 offers.

Which has higher FP16 performance?

B300 achieves 2250 TFLOPS FP16, over 117 times A4000's 19.2 TFLOPS. This gap favors B300 for AI training.

What are the power requirements?

B300 demands 1200W TDP in SXM form factor with NVLink. A4000 uses 140W in PCIe, ideal for workstations.

Is memory bandwidth a key differentiator?

B300 delivers 12000 GB/s, 27 times A4000's 448 GB/s. Higher bandwidth on B300 supports larger batches in inference.

When was each architecture released?

Blackwell Ultra for B300 launched in 2025. Ampere for A4000 dates to 2021.

Which is cheaper to rent, the B300 or the RTX A4000?

Cloud rental prices for both the B300 and RTX A4000 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 B300 have compared to the RTX A4000?

The B300 has 288 GB of HBM3e memory. The RTX A4000 has 16 GB of GDDR6 memory.

Can I find B300 and RTX A4000 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 B300 and the RTX A4000?

The B300 uses the Blackwell Ultra architecture (2025) while the RTX A4000 uses Ampere (2021). The B300 delivers 117.2x the FP16 throughput and 26.8x the memory bandwidth of the RTX A4000.

B300 SXM6 vs RTX A4000: 117.2x FP16 Gap, 288GB vs 16GB | GPUPerHour