A100 PCIe 40GB vs RTX 5090

AmperevsBlackwellUpdated 35 days ago

For the most common use case of LLM inference and fine-tuning, the RTX 5090 emerges as the winner. It provides higher FP16 at 419 TFLOPS, FP8 at 838 TFLOPS, and dramatically better FP32 at 105 TFLOPS, all at under half the average hourly rate of $0.65 versus $1.85. Superior compute per dollar outweighs the A100's bandwidth in price-driven cloud workflows.

A100 PCIe 40GB from $0.73/hrRTX 5090 from $0.57/hr

Specifications Compared

SpecA100RTX-5090
TDP400W575W
VRAM40-80 GB32 GB
CUDA Cores6,91221,760
Memory TypeHBM2eGDDR7
ArchitectureAmpereBlackwell
Form FactorsSXM4, PCIePCIe
InterconnectNVLink, PCIe 4.0, InfiniBandPCIe 5.0
Tensor Cores432680
FP16 Performance312 TFLOPS419 TFLOPS
FP32 Performance19.5 TFLOPS105 TFLOPS
FP64 Performance9.7 TFLOPS1.6 TFLOPS
INT8 Performance624 TOPS838 TOPS
Memory Bandwidth2,039 GB/s1,792 GB/s

Performance Analysis

The RTX 5090 outperforms the A100 in key compute metrics: FP16 reaches 419 TFLOPS versus 312 TFLOPS, accelerating half-precision training and inference in deep learning models. FP32 performance shows a larger gap at 105 TFLOPS compared to 19.5 TFLOPS, benefiting scientific simulations and graphics rendering that rely on single-precision arithmetic. The RTX 5090's FP8 capability at 838 TFLOPS further optimizes low-precision inference for large language models, reducing latency in deployment scenarios. However, the A100's 2039 GB/s bandwidth exceeds the RTX 5090's 1792 GB/s, enabling larger batch sizes in memory-intensive tasks like transformer training. This bandwidth edge sustains higher throughput when VRAM limits model scale, as the A100's 40 GB HBM2e holds more parameters than the RTX 5090's 32 GB GDDR7. In practice, these differences mean the A100 excels in multi-GPU clusters via NVLink and PCIe 4.0, while the RTX 5090 leverages PCIe 5.0 for single-GPU efficiency. Power draw impacts scaling: 400W for A100 versus 575W for RTX 5090 influences cloud costs in dense deployments.

Live Cloud Pricing

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

A100 PCIe 40GB

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×)

RTX 5090

ProviderGPU ModelVRAMHost SpecsRegionPriceStatusAction
TensorDock
TensorDock
NVIDIA GeForce RTX 5090
32GB VRAM
$0.57/GPU/hr
Available
Vast.ai
Vast.ai
NVIDIA GeForce RTX 5090
32GB VRAM
$0.81/GPU/hr
Available
Vast.ai
Vast.ai
NVIDIA GeForce RTX 5090
32GB VRAM
$0.87/GPU/hr
Available
Vast.ai
Vast.ai
NVIDIA GeForce RTX 5090
32GB VRAM
$0.87/GPU/hr
Available
Vast.ai
Vast.ai
NVIDIA GeForce RTX 5090
32GB VRAM
$0.91/GPU/hr
Available

Compare real-time pricing across 25+ providers

When to Choose the A100 PCIe 40GB

The A100 PCIe 40GB suits enterprise-scale AI training where 40 GB HBM2e VRAM and 2039 GB/s bandwidth handle massive datasets and large batch sizes. NVLink and InfiniBand interconnects enable efficient multi-GPU communication, ideal for distributed training of models exceeding 32 GB. Datacenter reliability and PCIe 4.0 compatibility ensure stability in production environments, despite higher pricing from $0.60/hr.

When to Choose the RTX 5090

The RTX 5090 delivers superior value for cost-sensitive inference and fine-tuning with FP16 at 419 TFLOPS and FP8 at 838 TFLOPS, outperforming the A100's 312 TFLOPS FP16. Its 105 TFLOPS FP32 crushes the A100's 19.5 TFLOPS for graphics and simulation workloads, at a fraction of the cost from $0.16/hr. PCIe 5.0 supports modern single-node setups with ample cloud availability across 28 offers.

Use Cases

LLM Training
A100 PCIe 40GB

The A100's 40 GB HBM2e VRAM and 2039 GB/s bandwidth support larger models and batch sizes critical for training. NVLink enables efficient multi-GPU scaling absent in the RTX 5090.

LLM Inference
RTX 5090

RTX 5090's FP8 at 838 TFLOPS and FP16 at 419 TFLOPS accelerate low-precision serving. Lower pricing from $0.16/hr makes it ideal for high-volume deployments.

Fine-tuning
RTX 5090

Higher FP16 at 419 TFLOPS and FP32 at 105 TFLOPS speed iterative tuning tasks. Cost efficiency at average $0.65/hr versus $1.85/hr favors the RTX 5090.

Stable Diffusion
RTX 5090

RTX 5090's 105 TFLOPS FP32 excels in image generation pipelines. Gaming-optimized architecture handles diffusion models efficiently at PCIe 5.0 speeds.

Scientific Computing
Either

A100's bandwidth suits memory-bound simulations; RTX 5090's FP32 at 105 TFLOPS aids compute-heavy tasks. Choice depends on VRAM needs versus raw FLOPS.

Frequently Asked Questions

Which GPU has more VRAM?

The A100 PCIe 40GB provides 40 GB HBM2e VRAM, exceeding the RTX 5090's 32 GB GDDR7. This advantage supports larger models in training. Bandwidth also favors A100 at 2039 GB/s over 1792 GB/s.

What is the price difference in cloud rentals?

RTX 5090 starts at $0.16/hr with average $0.65/hr across 28 offers, versus A100's $0.60/hr start and $1.85/hr average across 11 offers. This makes RTX 5090 far more affordable. Availability boosts RTX 5090 options.

Which is better for FP16 performance?

RTX 5090 leads with 419 TFLOPS FP16 against A100's 312 TFLOPS. This boosts training and inference speed. FP8 at 838 TFLOPS on RTX 5090 adds inference gains.

How do TDPs compare?

A100 consumes 400W TDP, lower than RTX 5090's 575W. Lower power aids dense cloud scaling for A100. Higher TDP on RTX 5090 correlates with peak performance.

What interconnects do they support?

A100 includes NVLink, PCIe 4.0, and InfiniBand for multi-GPU clusters. RTX 5090 relies on PCIe 5.0 for single-node use. A100 excels in distributed setups.

Is Blackwell architecture worth the switch from Ampere?

Blackwell in RTX 5090 offers FP32 at 105 TFLOPS versus Ampere A100's 19.5 TFLOPS, plus FP8 support. Pricing at $0.16/hr from justifies upgrades for compute-heavy tasks. A100 retains bandwidth edge.

Which is cheaper to rent, the A100 or the RTX 5090?

Cloud rental prices for both the A100 and RTX 5090 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 RTX 5090?

The A100 has 40 to 80 GB of HBM2e memory. The RTX 5090 has 32 GB of GDDR7 memory.

Can I find A100 and RTX 5090 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 RTX 5090?

The A100 uses the Ampere architecture (2020) while the RTX 5090 uses Blackwell (2025). The RTX 5090 delivers 1.3x the FP16 throughput and 1.1x the memory bandwidth of the A100.

A100 PCIe 40GB vs RTX 5090: 80GB HBM2e vs 32GB GDDR7 | GPUPerHour