MI325X vs RTX 3090 Ti

CDNA 3vsAmpereUpdated 35 days ago

The MI325X emerges as the clear winner for AI and HPC workloads: its 37x FP16 advantage, 256 GB VRAM, and 6000 GB/s bandwidth enable unprecedented scale for training and inference, rendering the RTX 3090 Ti obsolete for professional use despite lower cost.

RTX 3090 Ti from $0.20/hr

Specifications Compared

SpecMI325XRTX-3090
TDP750W350W
VRAM256 GB24 GB
Memory TypeHBM3eGDDR6X
ArchitectureCDNA 3Ampere
Form FactorsOAMPCIe
InterconnectInfinity FabricNVLink
FP8 Performance2,614 TFLOPS
FP16 Performance1,307 TFLOPS35.6 TFLOPS
FP32 Performance1307 TFLOPS35.6 TFLOPS
FP64 Performance40.9 TFLOPS
INT8 Performance2,614 TOPS
Memory Bandwidth6,000 GB/s936 GB/s

Performance Analysis

The MI325X's 1307 TFLOPS FP16 and FP32 throughput crushes the RTX 3090 Ti's 35.6 TFLOPS: this translates to roughly 37 times faster tensor core operations for deep learning training and inference. Training large language models benefits immensely, as the MI325X processes batches with minimal stalls thanks to its 6000 GB/s bandwidth supporting 256 GB VRAM for models exceeding 100 billion parameters.

Memory bandwidth disparity proves critical for inference: the MI325X handles massive batch sizes without swapping to host RAM, sustaining high throughput in FP8 at 2614 TFLOPS for low-latency serving. The RTX 3090 Ti, limited to 936 GB/s and 24 GB VRAM, suits smaller models or fine-tuning but bottlenecks on datasets over 20 GB. Power efficiency favors the RTX 3090 Ti at 350W versus 750W, yet raw compute favors datacenter scales.

Live Cloud Pricing

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

RTX 3090 Ti

ProviderGPU ModelVRAMHost SpecsRegionPriceStatusAction
TensorDock
TensorDock
NVIDIA GeForce RTX 3090
24GB VRAM
$0.20/GPU/hr
Available
TensorDock
TensorDock
NVIDIA GeForce RTX 3090
24GB VRAM
$0.21/GPU/hr
Available
Vast.ai
Vast.ai
4×NVIDIA GeForce RTX 3090
24GB VRAM
$0.25/GPU/hr
$1.01/hr total (4×)
Available
Vast.ai
Vast.ai
4×NVIDIA GeForce RTX 3090
24GB VRAM
$0.27/GPU/hr
$1.07/hr total (4×)
Available
LeaderGPU
LeaderGPU
8×NVIDIA GeForce RTX 3090
24GB VRAM
$0.29/GPU/hr
$2.29/hr total (8×)
Available

Compare real-time pricing across 25+ providers

When to Choose the MI325X

The MI325X excels in hyperscale AI training and inference where VRAM exceeds 100 GB: its 256 GB HBM3e enables loading full models like 405B-parameter LLMs without sharding. Enterprise teams prioritize it for production inference at 2614 TFLOPS FP8, handling thousands of queries per second across clusters via Infinity Fabric.

When to Choose the RTX 3090 Ti

The RTX 3090 Ti fits budget-conscious prototyping and gaming-enhanced workflows: at $0.10 per hour average, it delivers 35.6 TFLOPS FP32 for fine-tuning models under 20 GB. Hobbyists and small teams choose it for PCIe compatibility and NVLink in multi-GPU setups without datacenter infrastructure.

Use Cases

LLM Training
MI325X

The MI325X's 1307 TFLOPS FP16 and 256 GB VRAM support training models over 100B parameters without partitioning. The RTX 3090 Ti's 24 GB limits it to smaller scales.

LLM Inference
MI325X

MI325X FP8 at 2614 TFLOPS and 6000 GB/s bandwidth enable high-throughput serving of massive models. RTX 3090 Ti bottlenecks on large batches due to 936 GB/s.

Fine-tuning
Either

RTX 3090 Ti suffices for models under 20 GB at 35.6 TFLOPS and $0.10/hr. MI325X overkill unless datasets exceed 100 GB.

Stable Diffusion
RTX 3090 Ti

RTX 3090 Ti's 24 GB GDDR6X handles image generation efficiently at lower cost. MI325X's 750W TDP unnecessary for consumer creative tasks.

Scientific Computing
MI325X

MI325X 1307 TFLOPS FP32 accelerates simulations with huge datasets via 256 GB VRAM. RTX 3090 Ti inadequate for petabyte-scale analysis.

Frequently Asked Questions

Which GPU has more VRAM?

The MI325X offers 256 GB HBM3e VRAM. The RTX 3090 Ti provides 24 GB GDDR6X, making MI325X over 10 times larger for massive models.

What is the memory bandwidth difference?

MI325X achieves 6000 GB/s with HBM3e. RTX 3090 Ti reaches 936 GB/s, a 6.4x gap favoring larger batch processing on MI325X.

How do FP16 performances compare?

MI325X delivers 1307 TFLOPS FP16. RTX 3090 Ti offers 35.6 TFLOPS, approximately 37 times less for AI acceleration.

What are the power requirements?

MI325X has a 750W TDP for datacenter use. RTX 3090 Ti consumes 350W, suiting consumer builds.

Is there cloud pricing available?

MI325X has no live offers currently. RTX 3090 Ti starts at $0.10/hr average $0.25/hr across 5 providers.

Which supports larger AI models?

MI325X with 256 GB VRAM loads models up to 500B parameters unpartitioned. RTX 3090 Ti maxes at around 20 GB models.

Which is cheaper to rent, the MI325X or the RTX 3090?

Cloud rental prices for both the MI325X and RTX 3090 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 MI325X have compared to the RTX 3090?

The MI325X has 256 GB of HBM3e memory. The RTX 3090 has 24 GB of GDDR6X memory.

Can I find MI325X and RTX 3090 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 MI325X and the RTX 3090?

The MI325X uses the CDNA 3 architecture (2024) while the RTX 3090 uses Ampere (2020). The MI325X delivers 36.7x the FP16 throughput and 6.4x the memory bandwidth of the RTX 3090.

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