A100 PCIe 40GB vs MI325X

AmperevsCDNA 3Updated 35 days ago

MI325X emerges as the winner for demanding AI use cases: 256 GB VRAM, 6000 GB/s bandwidth, and 1307 TFLOPS FP16/FP32 provide overwhelming advantages over A100's 40 GB, 2039 GB/s, and 312/19.5 TFLOPS. A100 remains viable where availability and cost prevail, given its $0.60/hr starting price.

A100 PCIe 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

MI325X demonstrates superior memory capacity: 256 GB HBM3e versus A100's 40 GB HBM2e allows single-GPU operation for models exceeding 40 GB, minimizing sharding complexity in LLM training. Its 6000 GB/s bandwidth dwarfs A100's 2039 GB/s, enabling larger batch sizes that accelerate training epochs and improve inference throughput for memory-bound tasks.

A100's FP16 performance at 312 TFLOPS supports mixed-precision training effectively, yet its FP32 at 19.5 TFLOPS trails MI325X's balanced 1307 TFLOPS in both formats, favoring MI325X for precision-sensitive simulations or inference. MI325X's FP8 capability at 2614 TFLOPS further boosts quantized inference speeds, reducing latency in deployment scenarios. Higher TDP of 750W on MI325X versus 400W on A100 reflects its compute density.

Live Cloud Pricing

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

A100 PCIe 40GB

ProviderGPU ModelVRAMHost SpecsRegionPriceStatusAction
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
2×NVIDIA A100 SXM4 80GB
80GB VRAM
$1.00/GPU/hr
$2.00/hr total (2×)
Available
Denvr
Denvr
4×NVIDIA A100 PCIe 80GB
80GB VRAM
$1.15/GPU/hr
$4.60/hr total (4×)
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 PCIe 40GB

NVIDIA A100 PCIe 40GB excels in cost-effective, immediately available cloud deployments: pricing starts at $0.60/hr with an average of $1.85/hr across 11 live offers. Its 400W TDP suits power-limited environments better than MI325X's 750W. Established interconnects like NVLink, PCIe 4.0, and InfiniBand ensure seamless integration in mature NVIDIA ecosystems for medium-scale AI tasks fitting within 40 GB VRAM.

When to Choose the MI325X

AMD Instinct MI325X dominates large-model workloads: 256 GB HBM3e VRAM handles massive LLMs without multi-GPU setups, unlike A100's 40 GB limit. Bandwidth of 6000 GB/s supports expansive batch sizes, and 1307 TFLOPS FP16/FP32 outperforms A100's 312/19.5 TFLOPS for faster training and inference. Infinity Fabric interconnect aids AMD cluster scaling for data centers prioritizing peak performance.

Use Cases

LLM Training
MI325X

MI325X's 256 GB VRAM and 6000 GB/s bandwidth enable larger batches for models exceeding A100's 40 GB capacity. Its 1307 TFLOPS FP16 outperforms A100's 312 TFLOPS, speeding up epochs.

LLM Inference
MI325X

MI325X supports serving huge models on one GPU with 256 GB VRAM and 2614 TFLOPS FP8. Bandwidth of 6000 GB/s handles high concurrency better than A100's 2039 GB/s.

Fine-tuning
A100 PCIe 40GB

A100's 40 GB VRAM suffices for most fine-tuning datasets, with availability at $0.60/hr. Lower 400W TDP fits smaller setups versus MI325X's 750W.

Stable Diffusion
Either

Both handle image generation well: A100's 312 TFLOPS FP16 fits typical workflows affordably, while MI325X's higher specs accelerate larger-scale diffusion models.

Scientific Computing
MI325X

MI325X's 1307 TFLOPS FP32 and 6000 GB/s bandwidth excel in simulations versus A100's 19.5 TFLOPS FP32 and 2039 GB/s.

Frequently Asked Questions

Which GPU has more VRAM?

MI325X offers 256 GB HBM3e, far exceeding A100 PCIe 40GB's 40 GB HBM2e. This enables MI325X to load larger models without partitioning. A100 suits smaller workloads within its limit.

What are the cloud prices?

A100 PCIe 40GB starts at $0.60/hr, averaging $1.85/hr across 11 offers. MI325X has no live cloud offers currently. A100 provides immediate access.

How do FP16 performances compare?

MI325X delivers 1307 TFLOPS FP16, over four times A100's 312 TFLOPS. This boosts mixed-precision training on MI325X. A100 remains capable for legacy tasks.

What is the power consumption?

A100 has a 400W TDP, lower than MI325X's 750W. A100 fits constrained power budgets better. MI325X justifies higher draw with superior specs.

Which is better for LLM inference?

MI325X excels with 256 GB VRAM, 6000 GB/s bandwidth, and 2614 TFLOPS FP8. It serves massive models efficiently versus A100's 40 GB limit. A100 works for smaller LLMs.

What architectures do they use?

A100 uses NVIDIA Ampere from 2020, MI325X uses AMD CDNA 3 from 2024. MI325X incorporates newer HBM3e memory. A100 benefits from broader software maturity.

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 PCIe 40GB vs MI325X: NVIDIA 80GB vs AMD 256GB | GPUPerHour