A40 vs MI355X

AmperevsCDNA 4Updated 35 days ago

The MI355X emerges as the superior choice for performance-critical AI and HPC workloads. Its 2300 TFLOPS FP16/FP32 and 288 GB VRAM dwarf the A40's 37.4 TFLOPS and 48 GB, enabling larger models and faster training. While availability favors the A40 at $0.24 per hour, the MI355X defines future dominance once deployed.

A40 from $0.08/hr

Specifications Compared

SpecA40MI355X
TDP300W750W
VRAM48 GB288 GB
CUDA Cores10,752
Memory TypeGDDR6HBM3e
ArchitectureAmpereCDNA 4
Form FactorsPCIeOAM
InterconnectNVLinkInfinity Fabric
Tensor Cores336
FP16 Performance37.4 TFLOPS2,300 TFLOPS
FP32 Performance37.4 TFLOPS2300 TFLOPS
FP64 Performance0.6 TFLOPS72 TFLOPS
INT8 Performance299 TOPS4,600 TOPS
Memory Bandwidth696 GB/s8,000 GB/s

Performance Analysis

Compute performance shows stark contrasts: the MI355X delivers 2300 TFLOPS in both FP16 and FP32, compared to the A40's 37.4 TFLOPS, a 61-fold increase. This delta accelerates deep learning training, where FP16 precision dominates, and FP32 for scientific simulations. Inference benefits similarly, with the MI355X's FP8 at 4600 TFLOPS enabling ultra-fast low-precision deployments.

Memory specifications define workload scalability. The MI355X's 288 GB HBM3e VRAM supports models exceeding 48 GB, the A40's limit, allowing larger batch sizes in training. Its 8000 GB/s bandwidth versus 696 GB/s reduces bottlenecks, sustaining high throughput for memory-intensive tasks like large language model processing.

Power and form factors influence deployment. The A40's 300W TDP enables efficient cooling in standard PCIe slots, while the MI355X's 750W demands robust infrastructure in OAM setups. These traits position the MI355X for peak performance in dense clusters, though the A40 excels in power-constrained environments.

Live Cloud Pricing

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

A40

ProviderGPU ModelVRAMHost SpecsRegionPriceStatusAction
TensorDock
TensorDock
NVIDIA RTX A4000
16GB VRAM
$0.08/GPU/hr
Available
Vast.ai
Vast.ai
8×NVIDIA RTX A4000
16GB VRAM
$0.15/GPU/hr
$1.17/hr total (8×)
Available
Hyperstack
Hyperstack
2×NVIDIA RTX A4000
16GB VRAM
$0.15/GPU/hr
$0.30/hr total (2×)
Available
Hyperstack
Hyperstack
NVIDIA RTX A4000
16GB VRAM
$0.15/GPU/hr
Available
Vast.ai
Vast.ai
8×NVIDIA RTX A4000
16GB VRAM
$0.16/GPU/hr
$1.28/hr total (8×)
Available

Compare real-time pricing across 25+ providers

When to Choose the A40

The A40 suits budget-conscious deployments with proven NVIDIA software ecosystem. At $0.24 per hour minimum pricing across 23 offers, it handles workloads fitting within 48 GB VRAM, such as fine-tuning mid-sized models or Stable Diffusion generation. Its 300W TDP and PCIe compatibility simplify integration into existing data centers without high power upgrades.

Immediate availability makes the A40 ideal for production inference on models under 37.4 TFLOPS FP16 demands, avoiding delays from the MI355X's lack of live offers.

When to Choose the MI355X

The MI355X excels in demanding AI training and inference requiring massive scale. Its 288 GB HBM3e VRAM accommodates enormous models, and 8000 GB/s bandwidth supports huge batch sizes, far beyond the A40's 48 GB and 696 GB/s.

Users prioritizing raw compute choose it for 2300 TFLOPS FP16/FP32 or 4600 TFLOPS FP8, ideal for next-generation HPC despite 750W TDP and OAM form factor.

Use Cases

LLM Training
MI355X

The MI355X's 288 GB VRAM and 2300 TFLOPS FP16 handle massive parameter counts and large batches. The A40's 48 GB limits scale at 37.4 TFLOPS.

LLM Inference
MI355X

FP8 at 4600 TFLOPS and 8000 GB/s bandwidth enable high-throughput serving. The A40's 696 GB/s and lower compute constrain volume.

Fine-tuning
MI355X

2300 TFLOPS FP16 accelerates iterations on large models within 288 GB. A40 suffices for smaller tasks but bottlenecks at 48 GB.

Stable Diffusion
A40

A40's 48 GB VRAM and 37.4 TFLOPS FP16 meet image generation needs efficiently at low $0.24 per hour cost. MI355X overkill.

Scientific Computing
MI355X

MI355X's 2300 TFLOPS FP32 and high bandwidth speed simulations. A40's 37.4 TFLOPS limits complex datasets.

Frequently Asked Questions

What is the VRAM difference between A40 and MI355X?

The A40 has 48 GB GDDR6 VRAM. The MI355X offers 288 GB HBM3e, six times more capacity for larger models.

How do FP16 performances compare?

A40 achieves 37.4 TFLOPS in FP16. MI355X reaches 2300 TFLOPS, a 61 times increase for faster AI training.

What are the current cloud prices for these GPUs?

A40 starts at $0.24 per hour, averaging $1.26 across 23 offers. MI355X has no live offers available.

Which has higher memory bandwidth?

MI355X provides 8000 GB/s with HBM3e. A40 offers 696 GB/s with GDDR6, over 11 times less.

What are the TDP ratings?

A40 consumes 300W. MI355X requires 750W, demanding advanced cooling.

What interconnects do they use?

A40 uses NVLink. MI355X employs Infinity Fabric for cluster scaling.

Which is cheaper to rent, the A40 or the MI355X?

Cloud rental prices for both the A40 and MI355X 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 A40 have compared to the MI355X?

The A40 has 48 GB of GDDR6 memory. The MI355X has 288 GB of HBM3e memory.

Can I find A40 and MI355X 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 A40 and the MI355X?

The A40 uses the Ampere architecture (2020) while the MI355X uses CDNA 4 (2025). The MI355X delivers 61.5x the FP16 throughput and 11.5x the memory bandwidth of the A40.

A40 vs MI355X: NVIDIA 48GB vs AMD 288GB | GPUPerHour