A100 vs MI325X

AmperevsCDNA 3Updated 36 days ago

The MI325X emerges as the superior choice for most common use cases like LLM training and inference. Its 256 GB VRAM and 6000 GB/s bandwidth address memory limitations of the A100's 80 GB maximum, enabling larger models and batches. Despite higher 750W TDP and lack of current pricing, raw specs position it ahead for demanding AI workloads.

A100 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

Memory specifications define key advantages: the MI325X's 256 GB HBM3e VRAM dwarfs the A100's 40 to 80 GB HBM2e, enabling larger models or batch sizes without swapping. Its 6000 GB/s bandwidth, versus 2039 GB/s, accelerates data transfers, reducing bottlenecks in memory-bound tasks like LLM training.

Compute differences highlight architecture shifts. The A100's FP16 at 312 TFLOPS suits mixed-precision training, but its FP32 at 19.5 TFLOPS limits single-precision workloads. The MI325X balances both at 1307 TFLOPS and adds FP8 at 2614 TFLOPS, optimizing inference for quantized models. This balance supports versatile AI pipelines.

Power demands reflect performance: the MI325X's 750W TDP exceeds the A100's 400W, implying higher infrastructure costs but superior throughput per watt in high-end scenarios.

Live Cloud Pricing

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

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 A100

The A100 excels in production environments requiring immediate availability. With 59 live cloud offers from $0.45 per hour, it enables rapid scaling for LLM fine-tuning or inference without delays. Its 400W TDP fits power-constrained clusters, and mature NVLink support ensures reliable multi-GPU training.

Legacy workflows benefit from the A100's ecosystem, including optimized CUDA software stacks absent in the newer MI325X.

When to Choose the MI325X

The MI325X suits memory-intensive applications like training massive LLMs. Its 256 GB VRAM handles models exceeding 80 GB, while 6000 GB/s bandwidth supports enormous batch sizes. Balanced 1307 TFLOPS FP16 and FP32 performance accelerates both training and precision-sensitive simulations.

Forward-looking deployments favor the MI325X for its FP8 capabilities at 2614 TFLOPS, ideal for efficient inference at scale.

Use Cases

LLM Training
MI325X

The MI325X's 256 GB VRAM and 6000 GB/s bandwidth handle massive datasets and large batch sizes better than the A100's 80 GB maximum. Its 1307 TFLOPS FP16 outperforms the A100's 312 TFLOPS for accelerated training.

LLM Inference
MI325X

FP8 performance at 2614 TFLOPS on the MI325X optimizes quantized inference for high throughput. The 256 GB VRAM supports serving larger models without fragmentation issues seen in the A100.

Fine-tuning
Either

A100's availability at $0.45 per hour suits quick iterations, while MI325X's higher bandwidth aids larger fine-tuning batches. Choice depends on model size and urgency.

Stable Diffusion
MI325X

MI325X's 1307 TFLOPS FP32 matches its FP16 for diffusion model generation, surpassing A100's 19.5 TFLOPS FP32. Vast VRAM enables high-resolution image batches.

Scientific Computing
MI325X

Balanced FP32 at 1307 TFLOPS on MI325X excels in simulations requiring precision, far beyond A100's 19.5 TFLOPS. Infinity Fabric aids multi-node scaling.

Frequently Asked Questions

Which has more VRAM: A100 or MI325X?

The MI325X provides 256 GB HBM3e VRAM, compared to the A100's 40 to 80 GB HBM2e. This difference allows the MI325X to load much larger AI models in memory.

What is the memory bandwidth difference between A100 and MI325X?

MI325X offers 6000 GB/s, nearly triple the A100's 2039 GB/s. Higher bandwidth reduces data movement latency for training and inference.

Is MI325X available on cloud providers?

No live cloud offers exist for MI325X currently. A100 has 59 offers from $0.45 per hour averaging $1.91 per hour.

How do FP16 performances compare?

MI325X achieves 1307 TFLOPS FP16, over four times the A100's 312 TFLOPS. This boosts mixed-precision AI training speeds.

What are the power requirements?

A100 has a 400W TDP, while MI325X requires 750W. Higher TDP correlates with MI325X's superior compute and memory specs.

Which is better for LLM inference?

MI325X leads with FP8 at 2614 TFLOPS and 256 GB VRAM for quantized large models. A100 remains viable for smaller deployments due to availability.

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.