A40 vs B300 SXM6

AmperevsBlackwell UltraUpdated 35 days ago

The B300 wins for dominant AI use cases like LLM training and inference due to 60 times FP16 uplift to 2250 TFLOPS and 288 GB VRAM enabling unprecedented scales. A40 lags in modern workloads despite lower $1.26 per hour pricing, making B300 the choice for performance-critical cloud rentals.

A40 from $0.08/hrB300 SXM6 from $7.39/hr

Specifications Compared

SpecA40B300
TDP300W1200W
VRAM48 GB288 GB
CUDA Cores10,752
Memory TypeGDDR6HBM3e
ArchitectureAmpereBlackwell Ultra
Form FactorsPCIeSXM
InterconnectNVLinkNVSwitch, NVLink
Tensor Cores336
FP16 Performance37.4 TFLOPS2,250 TFLOPS
FP32 Performance37.4 TFLOPS90 TFLOPS
FP64 Performance0.6 TFLOPS45 TFLOPS
INT8 Performance299 TOPS4,500 TOPS
Memory Bandwidth696 GB/s12,000 GB/s

Performance Analysis

The B300 vastly outperforms the A40 in compute: 2250 TFLOPS FP16 versus 37.4 TFLOPS enables over 60 times faster half-precision training for large language models. Its FP32 rate of 90 TFLOPS exceeds the A40's 37.4 TFLOPS by 2.4 times, benefiting single-precision scientific simulations. The FP8 capability of 4500 TFLOPS on B300 accelerates inference for quantized models, absent on A40.

Memory differences reshape workloads: B300's 288 GB HBM3e supports batch sizes up to six times larger than A40's 48 GB GDDR6 limit, reducing overhead in LLM training. The 12000 GB/s bandwidth versus 696 GB/s minimizes bottlenecks in data-heavy inference, allowing sustained throughput. A40 suits smaller models where its PCIe form factor and 300W TDP enable dense clusters without cooling strain.

Live Cloud Pricing

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

A40

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
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
Vast.ai
Vast.ai
8×NVIDIA RTX A4000
16GB VRAM
$0.16/GPU/hr
$1.28/hr total (8×)
Available

B300 SXM6

ProviderGPU ModelVRAMHost SpecsRegionPriceStatusAction
RunPod
RunPod
NVIDIA B300 SXM6
262GB VRAM
$7.39/GPU/hr
VERDA
VERDA
NVIDIA B300 SXM6
262GB VRAM
$7.50/GPU/hr
Available
VERDA
VERDA
2×NVIDIA B300 SXM6
262GB VRAM
$7.50/GPU/hr
$15.00/hr total (2×)
Available
VERDA
VERDA
8×NVIDIA B300 SXM6
262GB VRAM
$7.50/GPU/hr
$60.00/hr total (8×)
Available
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 A40

Select the A40 for cost-sensitive deployments under $1.26 per hour average pricing. Its 48 GB VRAM handles fine-tuning of models up to 30 billion parameters and Stable Diffusion at 512x512 resolutions efficiently. The 300W TDP and PCIe form factor fit legacy servers or edge computing without power overhauls.

It excels in visualization and moderate inference where 37.4 TFLOPS FP16 suffices, avoiding B300's $6.44 per hour cost for underutilized capacity.

When to Choose the B300 SXM6

Choose the B300 for massive-scale AI: 288 GB VRAM trains LLMs exceeding 1 trillion parameters without multi-GPU sharding. Its 2250 TFLOPS FP16 and 4500 TFLOPS FP8 deliver rapid training and quantized inference cycles.

High-bandwidth 12000 GB/s supports enormous batch sizes in production inference, justifying $6.44 per hour for throughput gains despite 1200W TDP and SXM form factor needs.

Use Cases

LLM Training
B300 SXM6

B300's 2250 TFLOPS FP16 and 288 GB HBM3e VRAM handle trillion-parameter models with large batches. A40's 37.4 TFLOPS and 48 GB limit it to smaller scales.

LLM Inference
B300 SXM6

B300's 4500 TFLOPS FP8 and 12000 GB/s bandwidth serve high-concurrency quantized inference. A40 cannot match throughput for production loads.

Fine-tuning
B300 SXM6

B300 accelerates fine-tuning with 90 TFLOPS FP32 and vast VRAM for full-model loading. A40 works for sub-30B models but scales poorly.

Stable Diffusion
A40

A40's 48 GB VRAM and 37.4 TFLOPS FP16 generate 1024x1024 images efficiently at $1.26 per hour. B300 overkill for consumer-scale diffusion.

Scientific Computing
B300 SXM6

B300's 90 TFLOPS FP32 and NVSwitch interconnect speed simulations like molecular dynamics. A40's PCIe limits multi-node scaling.

Frequently Asked Questions

What is the VRAM difference between A40 and B300?

A40 has 48 GB GDDR6 VRAM. B300 offers 288 GB HBM3e, enabling six times larger models or batches.

How do cloud prices compare for A40 vs B300?

A40 pricing starts at $0.24 per hour, averaging $1.26 per hour across 23 offers. B300 SXM6 begins at $2.45 per hour, averaging $6.44 per hour across 7 offers.

What are the FP16 performance specs?

A40 delivers 37.4 TFLOPS FP16. B300 achieves 2250 TFLOPS FP16, over 60 times higher for AI training.

Which has higher memory bandwidth?

B300 provides 12000 GB/s bandwidth. A40 reaches 696 GB/s, about 17 times less.

What is the TDP for each GPU?

A40 consumes 300W TDP in PCIe form. B300 requires 1200W TDP in SXM form factor.

Does B300 support FP8?

B300 includes 4500 TFLOPS FP8 for inference. A40 lacks FP8 capability.

Which is cheaper to rent, the A40 or the B300?

Cloud rental prices for both the A40 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 A40 have compared to the B300?

The A40 has 48 GB of GDDR6 memory. The B300 has 288 GB of HBM3e memory.

Can I find A40 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 A40 and the B300?

The A40 uses the Ampere architecture (2020) while the B300 uses Blackwell Ultra (2025). The B300 delivers 60.2x the FP16 throughput and 17.2x the memory bandwidth of the A40.

A40 vs B300 SXM6: 60.2x FP16 Gap, 288GB vs 48GB | GPUPerHour