RTX 4090 vs A100

Ada LovelacevsAmpereUpdated 40 days ago

The A100 emerges as the winner for prevalent AI training and large-model workloads due to its 312 TFLOPS FP16 performance, 2039 GB/s bandwidth, and 40-80 GB VRAM, which outperform the RTX 4090's specs despite higher average pricing of $1.33 per hour versus $0.39 per hour.

RTX 4090 from $0.39/hrA100 from $0.73/hr

Specifications Compared

SpecRTX-4090A100
TDP450W400W
VRAM24 GB40-80 GB
CUDA Cores16,3846,912
Memory TypeGDDR6XHBM2e
ArchitectureAda LovelaceAmpere
Form FactorsPCIeSXM4, PCIe
InterconnectPCIe 4.0NVLink, PCIe 4.0, InfiniBand
Tensor Cores512432
FP8 Performance660 TFLOPS
FP16 Performance165 TFLOPS312 TFLOPS
FP32 Performance82.6 TFLOPS19.5 TFLOPS
FP64 Performance1.3 TFLOPS9.7 TFLOPS
INT8 Performance660 TOPS624 TOPS
Memory Bandwidth1,008 GB/s2,039 GB/s

Performance Analysis

The A100 demonstrates dominance in FP16 performance at 312 TFLOPS over the RTX 4090's 165 TFLOPS, accelerating deep learning training where half-precision computations prevail and reducing epochs for models like transformers. This gap translates to faster convergence on datasets requiring tensor cores optimized for AI. Conversely, the RTX 4090's FP32 rate of 82.6 TFLOPS exceeds the A100's 19.5 TFLOPS, benefiting simulations or graphics workloads dependent on single-precision arithmetic.

Memory bandwidth profoundly impacts real-world usage: the A100's 2039 GB/s supports larger batch sizes and models with extensive parameters, minimizing data transfer bottlenecks during training. The RTX 4090's 1008 GB/s limits scalability for such scenarios but suffices for smaller batches. For inference, the RTX 4090's FP8 capability at 660 TFLOPS enables efficient quantized deployments, potentially lowering latency in production serving compared to the A100's focus on higher-precision throughput.

Power draw differs slightly with the RTX 4090 at 450W TDP versus the A100's 400W, influencing cluster density; interconnects like NVLink on the A100 enhance multi-GPU communication over PCIe 4.0 alone.

Live Cloud Pricing

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

RTX 4090

ProviderGPU ModelVRAMHost SpecsRegionPriceStatusAction
TensorDock
TensorDock
NVIDIA GeForce RTX 4090
24GB VRAM
$0.39/GPU/hr
Available
Vast.ai
Vast.ai
NVIDIA GeForce RTX 4090
24GB VRAM
$0.44/GPU/hr
Available
Vast.ai
Vast.ai
NVIDIA GeForce RTX 4090
24GB VRAM
$0.47/GPU/hr
Available
TensorDock
TensorDock
NVIDIA GeForce RTX 4090
24GB VRAM
$0.48/GPU/hr
Available
Vast.ai
Vast.ai
NVIDIA GeForce RTX 4090
24GB VRAM
$0.53/GPU/hr
Available

A100

ProviderGPU ModelVRAMHost SpecsRegionPriceStatusAction
Vast.ai
Vast.ai
NVIDIA A100 SXM4 80GB
80GB VRAM
$0.73/GPU/hr
Available
Vast.ai
Vast.ai
2×NVIDIA A100 SXM4 80GB
80GB VRAM
$0.73/GPU/hr
$1.47/hr total (2×)
Available
LeaderGPU
LeaderGPU
8×NVIDIA A100 PCIe 80GB
80GB VRAM
$0.90/GPU/hr
$7.20/hr total (8×)
Available
Vast.ai
Vast.ai
NVIDIA A100 SXM4 80GB
80GB VRAM
$1.07/GPU/hr
Available
Denvr
Denvr
8×NVIDIA A100 SXM4 80GB
80GB VRAM
$1.15/GPU/hr
$9.20/hr total (8×)

Compare real-time pricing across 25+ providers

When to Choose the RTX 4090

The RTX 4090 excels in budget-conscious deployments leveraging its average cloud pricing of $0.39 per hour, far below the A100's $1.33 per hour average. It outperforms in FP32 tasks at 82.6 TFLOPS and FP8 inference at 660 TFLOPS, ideal for single-GPU Stable Diffusion or fine-tuning smaller models within its 24 GB VRAM.

Solo developers or inference-heavy pipelines benefit from its PCIe simplicity and 1008 GB/s bandwidth for moderate batch sizes, avoiding the A100's variable higher costs.

When to Choose the A100

The A100 stands out for large-scale AI training requiring 40-80 GB HBM2e VRAM and 2039 GB/s bandwidth to process massive datasets without memory constraints. Its 312 TFLOPS FP16 performance accelerates LLM pretraining, where the RTX 4090's 24 GB and 165 TFLOPS fall short.

Multi-GPU clusters favor the A100's NVLink and InfiniBand support over PCIe 4.0, enabling efficient scaling for enterprise scientific computing or distributed fine-tuning.

Use Cases

LLM Training
A100

A100's 312 TFLOPS FP16 and 40-80 GB HBM2e VRAM manage billion-parameter models efficiently. RTX 4090's 165 TFLOPS and 24 GB limit scale.

LLM Inference
RTX 4090

RTX 4090's FP8 at 660 TFLOPS optimizes quantized serving for low-latency responses. A100 suits unquantized high-throughput but at higher cost.

Fine-tuning
A100

A100's 2039 GB/s bandwidth and NVLink support larger batches in multi-GPU setups. RTX 4090 works for small models but bottlenecks on memory.

Stable Diffusion
RTX 4090

RTX 4090's 82.6 TFLOPS FP32 and 24 GB VRAM handle image generation effectively at $0.39 per hour average. A100 overkill for consumer tasks.

Scientific Computing
A100

A100's interconnects and 312 TFLOPS FP16 enable HPC simulations across nodes. RTX 4090's PCIe limits distributed precision workloads.

Frequently Asked Questions

Which has more VRAM: RTX 4090 or A100?

The A100 provides 40-80 GB HBM2e VRAM, exceeding the RTX 4090's 24 GB GDDR6X. This allows the A100 to load larger models without swapping. RTX 4090 suffices for mid-sized tasks.

RTX 4090 vs A100 for AI training?

A100 leads with 312 TFLOPS FP16 versus RTX 4090's 165 TFLOPS, speeding training cycles. Its 2039 GB/s bandwidth supports bigger batches. RTX 4090 fits cost-limited single-node runs at $0.39 per hour average.

What is the memory bandwidth difference?

A100 offers 2039 GB/s, double the RTX 4090's 1008 GB/s. Higher bandwidth reduces training bottlenecks for data-heavy workloads. RTX 4090 performs adequately for inference.

RTX 4090 cloud pricing vs A100?

RTX 4090 starts at $0.27 per hour (average $0.39 per hour across 75 offers). A100 begins at $0.13 per hour but averages $1.33 per hour across 34 offers. RTX 4090 provides better value consistency.

Is A100 better for multi-GPU setups?

Yes, A100 supports NVLink, PCIe 4.0, and InfiniBand for scaling, unlike RTX 4090's PCIe 4.0 only. This enhances distributed training efficiency. RTX 4090 limits to single or basic multi-GPU.

FP32 performance: RTX 4090 or A100?

RTX 4090 delivers 82.6 TFLOPS FP32, surpassing A100's 19.5 TFLOPS. It favors FP32-dominant simulations. A100 prioritizes FP16 for AI.

Which is cheaper to rent, the RTX 4090 or the A100?

Cloud rental prices for both the RTX 4090 and A100 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 RTX 4090 have compared to the A100?

The RTX 4090 has 24 GB of GDDR6X memory. The A100 has 40 to 80 GB of HBM2e memory.

Can I find RTX 4090 and A100 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 RTX 4090 and the A100?

The RTX 4090 uses the Ada Lovelace architecture (2022) while the A100 uses Ampere (2020). The A100 delivers 1.9x the FP16 throughput and 2.0x the memory bandwidth of the RTX 4090.