MI355X vs RTX A4000

CDNA 4vsAmpereUpdated 35 days ago

MI355X emerges as the superior choice for AI and HPC workloads: 2300 TFLOPS FP16, 288 GB VRAM, and 8000 GB/s bandwidth deliver over 100x the capacity of A4000's 19.2 TFLOPS and 16 GB. While A4000 offers immediate low-cost access from $0.08 per hour, MI355X dominates demanding training and inference scenarios.

RTX A4000 from $0.08/hr

Specifications Compared

SpecMI355XRTX-A4000
TDP750W140W
VRAM288 GB16 GB
Memory TypeHBM3eGDDR6
ArchitectureCDNA 4Ampere
Form FactorsOAMPCIe
InterconnectInfinity Fabric
FP8 Performance4,600 TFLOPS
FP16 Performance2,300 TFLOPS19.2 TFLOPS
FP32 Performance2300 TFLOPS19.2 TFLOPS
FP64 Performance72 TFLOPS
INT8 Performance4,600 TOPS
Memory Bandwidth8,000 GB/s448 GB/s

Performance Analysis

MI355X's 288 GB HBM3e VRAM dwarfs A4000's 16 GB GDDR6, enabling single-GPU handling of models exceeding 100 billion parameters: A4000 requires model parallelism for anything larger. This VRAM advantage supports enormous batch sizes in training, reducing overhead from data loading.

The 8000 GB/s bandwidth on MI355X accelerates memory-bound operations like transformer attention layers, sustaining high throughput: A4000's 448 GB/s bottlenecks large batches, limiting effective utilization to 10-20% of peak in similar scenarios. FP16 and FP32 both hit 2300 TFLOPS on MI355X for balanced mixed-precision training; A4000 matches ratios at 19.2 TFLOPS but scales poorly overall. MI355X's FP8 at 4600 TFLOPS optimizes inference for quantized LLMs, far beyond A4000's capabilities.

Power draw reveals trade-offs: MI355X's 750W TDP suits dense racks with cooling, while A4000's 140W fits edge or low-power clouds, impacting total cost of ownership in efficiency-focused setups.

Live Cloud Pricing

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

RTX A4000

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
4×NVIDIA RTX A4000
16GB VRAM
$0.15/GPU/hr
$0.60/hr total (4×)
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

Compare real-time pricing across 25+ providers

When to Choose the MI355X

MI355X excels in large-scale LLM training and inference: its 288 GB VRAM and 2300 TFLOPS FP16 handle models up to 1 trillion parameters without sharding. High 8000 GB/s bandwidth supports batch sizes over 1000, ideal for data centers pursuing peak throughput despite 750W TDP.

Scientific simulations benefit from CDNA 4 optimizations and Infinity Fabric interconnect, enabling multi-GPU scaling for petabyte datasets.

When to Choose the RTX A4000

RTX A4000 suits budget-conscious users: cloud pricing starts at $0.08 per hour with an average of $0.31 per hour across 28 offers. Its 140W TDP and PCIe form factor enable deployment in standard servers without specialized cooling.

Moderate workloads like Stable Diffusion or fine-tuning small models leverage 16 GB VRAM and 19.2 TFLOPS FP32 efficiently, prioritizing availability over raw power.

Use Cases

LLM Training
MI355X

MI355X's 288 GB VRAM and 2300 TFLOPS FP16 support massive models and large batches without partitioning. A4000's 16 GB limits it to small-scale training.

LLM Inference
MI355X

4600 TFLOPS FP8 and 8000 GB/s bandwidth on MI355X enable high-throughput serving of quantized LLMs. A4000 struggles with models over 7B parameters.

Fine-tuning
Either

Small models fit A4000's 16 GB VRAM at 19.2 TFLOPS for cost efficiency from $0.08 per hour. Larger ones need MI355X's 288 GB.

Stable Diffusion
RTX A4000

A4000's 16 GB GDDR6 and 140W TDP handle image generation workflows affordably. MI355X overkill for typical 512x512 resolutions.

Scientific Computing
MI355X

MI355X's CDNA 4 architecture and Infinity Fabric scale simulations with 2300 TFLOPS FP32. A4000's 19.2 TFLOPS suits prototypes only.

Frequently Asked Questions

Which has more VRAM: MI355X or RTX A4000?

MI355X provides 288 GB HBM3e VRAM. RTX A4000 offers 16 GB GDDR6. This enables MI355X for models 18 times larger.

What is the FP16 performance of MI355X vs A4000?

MI355X achieves 2300 TFLOPS FP16. A4000 reaches 19.2 TFLOPS. MI355X offers about 120 times higher throughput.

Is RTX A4000 cheaper in the cloud?

RTX A4000 starts at $0.08 per hour, averaging $0.31 per hour across 28 offers. MI355X has no live offers currently.

MI355X power consumption compared to A4000?

MI355X has 750W TDP. A4000 uses 140W. A4000 fits low-power environments better.

Memory bandwidth: MI355X or A4000?

MI355X delivers 8000 GB/s. A4000 provides 448 GB/s. MI355X supports nearly 18 times faster data movement.

Which GPU for LLM inference?

MI355X with 4600 TFLOPS FP8 and 288 GB VRAM excels for large models. A4000 works for small ones under 16 GB.

Which is cheaper to rent, the MI355X or the RTX A4000?

Cloud rental prices for both the MI355X and RTX A4000 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 MI355X have compared to the RTX A4000?

The MI355X has 288 GB of HBM3e memory. The RTX A4000 has 16 GB of GDDR6 memory.

Can I find MI355X and RTX A4000 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 MI355X and the RTX A4000?

The MI355X uses the CDNA 4 architecture (2025) while the RTX A4000 uses Ampere (2021). The MI355X delivers 119.8x the FP16 throughput and 17.9x the memory bandwidth of the RTX A4000.