A100 SXM4 40GB vs MI325X

AmperevsCDNA 3Updated 35 days ago

The AMD Instinct MI325X emerges as the superior choice for the most common use case of large-scale LLM training and inference. Its 256 GB VRAM and 6000 GB/s bandwidth enable massive models and batches infeasible on the A100's 40 GB and 2039 GB/s, while 1307 TFLOPS FP16 quadruples the A100's 312 TFLOPS for faster iterations.

A100 SXM4 40GB from $0.73/hr

Specifications Compared

SpecA100MI325X
TDP400W750W
VRAM40-80 GB256 GB
CUDA Cores6,912
Memory TypeHBM2eHBM3e
ArchitectureAmpereCDNA 3
Form FactorsSXM4, PCIeOAM
InterconnectNVLink, PCIe 4.0, InfiniBandInfinity Fabric
Tensor Cores432
FP16 Performance312 TFLOPS1,307 TFLOPS
FP32 Performance19.5 TFLOPS1307 TFLOPS
FP64 Performance9.7 TFLOPS40.9 TFLOPS
INT8 Performance624 TOPS2,614 TOPS
Memory Bandwidth2,039 GB/s6,000 GB/s

Performance Analysis

Peak FP16 performance reveals a stark contrast: the MI325X achieves 1307 TFLOPS versus the A100's 312 TFLOPS, enabling four times faster matrix multiplications central to deep learning training. The A100's FP32 rate of 19.5 TFLOPS lags far behind the MI325X's 1307 TFLOPS, a 67-fold gap that favors the latter for FP32-dominant simulations or certain inference pipelines. This balanced high FP16 and FP32 on the MI325X suits diverse precision needs, while the A100 excels in FP16-heavy mixed-precision training via tensor cores. Memory specifications transform real-world scalability. The MI325X's 256 GB HBM3e versus 40 GB HBM2e supports models with billions more parameters without aggressive sharding, and its 6000 GB/s bandwidth triples the A100's 2039 GB/s to minimize data movement bottlenecks. Larger batch sizes become feasible on the MI325X, reducing training iterations and wall-clock time for large language models. Higher 750 W TDP on the MI325X demands robust cooling, contrasting the A100's efficient 400 W.

Live Cloud Pricing

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

A100 SXM4 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×)

Compare real-time pricing across 25+ providers

When to Choose the A100 SXM4 40GB

The A100 SXM4 40GB suits immediate deployment needs with five live cloud offers from $1.00 per hour averaging $2.63 per hour. Its 400 W TDP consumes half the power of the MI325X's 750 W, lowering operational costs in power-constrained environments. Mature NVLink and InfiniBand support ensures reliable multi-GPU scaling for established workflows like fine-tuning mid-sized models up to 40 GB VRAM limits.

When to Choose the MI325X

The MI325X dominates memory-intensive tasks with 256 GB HBM3e versus 40 GB, handling unpartitioned large language models exceeding 100 billion parameters. Superior 6000 GB/s bandwidth and 1307 TFLOPS FP16 outperform the A100's 2039 GB/s and 312 TFLOPS, accelerating training and inference for cutting-edge AI. Future availability will appeal to high-scale HPC users prioritizing raw capacity over current pricing.

Use Cases

LLM Training
MI325X

The MI325X's 256 GB HBM3e VRAM supports training models over 100 billion parameters without multi-node sharding, unlike the A100's 40 GB limit. Its 1307 TFLOPS FP16 delivers four times the A100's 312 TFLOPS for quicker convergence.

LLM Inference
MI325X

MI325X handles large KV caches with 256 GB VRAM and 2614 TFLOPS FP8, far beyond A100's 40 GB capacity. Bandwidth of 6000 GB/s ensures low-latency serving versus 2039 GB/s.

Fine-tuning
Either

A100 suffices for models under 40 GB with available $1.00 per hour pricing and 312 TFLOPS FP16. MI325X excels for larger adapters via 256 GB VRAM but awaits offers.

Stable Diffusion
A100 SXM4 40GB

A100's 40 GB VRAM and 2039 GB/s bandwidth handle high-resolution generation at $2.63 per hour average. Lower 400 W TDP fits cost-sensitive creative workflows.

Scientific Computing
MI325X

MI325X's 1307 TFLOPS FP32 dwarfs A100's 19.5 TFLOPS for simulations. 256 GB VRAM processes vast datasets without paging.

Frequently Asked Questions

What is the VRAM difference between A100 SXM4 40GB and MI325X?

The A100 SXM4 40GB provides 40 GB HBM2e VRAM, while the MI325X offers 256 GB HBM3e. This six-fold increase allows the MI325X to load much larger models without distributed setups. Bandwidth follows suit at 6000 GB/s for MI325X versus 2039 GB/s.

How do FP16 performances compare?

MI325X delivers 1307 TFLOPS FP16, quadrupling the A100's 312 TFLOPS. This boosts training speed for matrix-heavy AI tasks on MI325X. FP32 also favors MI325X at 1307 TFLOPS over 19.5 TFLOPS.

What are the power requirements?

A100 SXM4 40GB has a 400 W TDP, half of the MI325X's 750 W. Lower power suits dense deployments on A100. MI325X demands advanced cooling for its higher compute.

Is MI325X available in the cloud yet?

No live cloud offers exist for MI325X currently. A100 SXM4 40GB starts at $1.00 per hour across five providers, averaging $2.63 per hour. Monitor gpuperhour.com for MI325X listings.

Which has better interconnects for multi-GPU?

A100 supports NVLink, PCIe 4.0, and InfiniBand for proven scaling. MI325X uses Infinity Fabric in OAM form. A100's ecosystem aids current clusters.

Can A100 handle large LLMs?

A100's 40 GB VRAM limits it to models under 70 billion parameters without sharding. MI325X's 256 GB fits full 405B models. Bandwidth of 2039 GB/s bottlenecks A100 at scale.

Which is cheaper to rent, the A100 or the MI325X?

Cloud rental prices for both the A100 and MI325X 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 MI325X?

The A100 has 40 to 80 GB of HBM2e memory. The MI325X has 256 GB of HBM3e memory.

Can I find A100 and MI325X 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 MI325X?

The A100 uses the Ampere architecture (2020) while the MI325X uses CDNA 3 (2024). The MI325X delivers 4.2x the FP16 throughput and 2.9x the memory bandwidth of the A100.

A100 SXM4 40GB vs MI325X: NVIDIA 80GB vs AMD 256GB | GPUPerHour