A40 vs GB300 SXM6

AmperevsBlackwell UltraUpdated 35 days ago

The GB300 emerges as the superior choice for most AI and machine learning use cases. Its 2250 TFLOPS FP16, 288 GB VRAM, and 12000 GB/s bandwidth vastly outperform A40's 37.4 TFLOPS and 696 GB/s, enabling faster training and larger models despite higher 1400W power draw and current unavailability.

A40 from $0.08/hr

Specifications Compared

SpecA40GB300
TDP300W1400W
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

Memory bandwidth presents the starkest contrast: GB300's 12000 GB/s dwarfs A40's 696 GB/s, allowing larger batch sizes in training and inference to process more data per iteration and accelerate convergence. This bandwidth supports handling massive datasets without bottlenecks, vital for large language models.

FP16 performance surges from A40's 37.4 TFLOPS to GB300's 2250 TFLOPS, optimizing mixed-precision training where speed gains reduce epochs significantly. FP32 holds at 37.4 TFLOPS for A40 versus 90 TFLOPS for GB300, maintaining balance for precision-sensitive simulations. GB300's FP8 at 4500 TFLOPS excels in inference, enabling high-throughput serving of quantized models.

Higher TDP of 1400W for GB300 versus 300W for A40 demands robust cooling but yields efficiency in flops per watt for intensive tasks. VRAM expansion to 288 GB from 48 GB accommodates models exceeding 100 billion parameters without multi-GPU sharding.

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

Compare real-time pricing across 25+ providers

When to Choose the A40

The A40 suits budget-limited projects or immediate deployments. With pricing from $0.24 per hour across 23 offers, it provides accessible entry for fine-tuning or inference on models fitting within 48 GB VRAM. Lower 300W TDP fits standard PCIe servers without specialized infrastructure.

Legacy workloads like Stable Diffusion or smaller scientific simulations leverage 37.4 TFLOPS FP16 effectively, avoiding overprovisioning costs.

When to Choose the GB300 SXM6

The GB300 targets frontier AI research and production-scale training. Its 288 GB HBM3e VRAM and 12000 GB/s bandwidth handle enormous models, while 2250 TFLOPS FP16 accelerates large-batch training. FP8 at 4500 TFLOPS optimizes high-volume inference.

Enterprise environments with NVSwitch support benefit from 1400W SXM scalability for clusters processing trillion-parameter models.

Use Cases

LLM Training
GB300 SXM6

GB300's 288 GB VRAM and 2250 TFLOPS FP16 support massive parameter counts and large batches. A40's 48 GB limits scale.

LLM Inference
GB300 SXM6

GB300's 4500 TFLOPS FP8 delivers high throughput for quantized serving. A40 lacks FP8 capability.

Fine-tuning
Either

A40 handles models under 48 GB at $0.24 per hour. GB300 excels for larger ones with 12000 GB/s bandwidth.

Stable Diffusion
A40

A40's 37.4 TFLOPS FP16 suffices for image generation within 48 GB VRAM. Lower cost and availability favor it.

Scientific Computing
GB300 SXM6

GB300's 90 TFLOPS FP32 and high bandwidth accelerate simulations. A40 works for modest scales.

Frequently Asked Questions

What is the VRAM difference between A40 and GB300?

The A40 has 48 GB GDDR6 VRAM. The GB300 provides 288 GB HBM3e, enabling six times more capacity for large models.

How do memory bandwidths compare?

A40 offers 696 GB/s. GB300 reaches 12000 GB/s, supporting over 17 times faster data movement for bigger batches.

What are the FP16 performance specs?

A40 delivers 37.4 TFLOPS FP16. GB300 achieves 2250 TFLOPS, a 60-fold increase for training acceleration.

Is cloud pricing available for these GPUs?

A40 has 23 live offers from $0.24 per hour, averaging $1.31 per hour. GB300 currently lists no live offers.

What are the power consumption differences?

A40 uses 300W TDP in PCIe form. GB300 requires 1400W in SXM, demanding advanced cooling.

Which has better interconnects?

A40 uses NVLink. GB300 employs NVSwitch and NVLink for superior multi-GPU scaling in clusters.

Which is cheaper to rent, the A40 or the GB300?

Cloud rental prices for both the A40 and GB300 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 GB300?

The A40 has 48 GB of GDDR6 memory. The GB300 has 288 GB of HBM3e memory.

Can I find A40 and GB300 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 GB300?

The A40 uses the Ampere architecture (2020) while the GB300 uses Blackwell Ultra (2025). The GB300 delivers 60.2x the FP16 throughput and 17.2x the memory bandwidth of the A40.

A40 vs GB300 SXM6: 60.2x FP16 Gap, 288GB vs 48GB | GPUPerHour