MI300X vs RTX 3090

CDNA 3vsAmpereUpdated 36 days ago

The MI300X emerges as the winner for most common AI use cases like LLM training and inference: 192 GB VRAM and 1307 TFLOPS FP16 enable handling massive models at 5300 GB/s bandwidth, unattainable by RTX 3090's 24 GB and 35.6 TFLOPS. Despite higher $2.63 per hour average cost, performance justifies it for production-scale workloads over RTX 3090's prototyping niche.

MI300X from $1.99/hrRTX 3090 from $0.20/hr

Specifications Compared

SpecMI300XRTX-3090
TDP750W350W
VRAM192 GB24 GB
Memory TypeHBM3GDDR6X
ArchitectureCDNA 3Ampere
Form FactorsOAMPCIe
InterconnectInfinity Fabric, PCIe 5.0NVLink
FP8 Performance2,614 TFLOPS
FP16 Performance1,307 TFLOPS35.6 TFLOPS
FP32 Performance163 TFLOPS35.6 TFLOPS
FP64 Performance81.7 TFLOPS
INT8 Performance2,614 TOPS
Memory Bandwidth5,300 GB/s936 GB/s

Performance Analysis

The MI300X outperforms the RTX 3090 dramatically in AI-relevant precisions: its 1307 TFLOPS FP16 dwarfs the 35.6 TFLOPS of the RTX 3090, enabling faster model training where half-precision dominates. The FP32 rating of 163 TFLOPS on MI300X exceeds the RTX 3090's 35.6 TFLOPS, benefiting general compute tasks. FP8 at 2614 TFLOPS positions MI300X for efficient large language model inference, a capability absent in the consumer-grade RTX 3090.

Memory specifications define real-world usability: 192 GB HBM3 on MI300X supports enormous batch sizes and models exceeding 24 GB GDDR6X limits on RTX 3090. Bandwidth of 5300 GB/s versus 936 GB/s accelerates data transfers, reducing bottlenecks in training loops with large datasets. This allows MI300X to process models like 70B-parameter LLMs without splitting, while RTX 3090 requires quantization or multi-GPU setups.

Power and interconnects further differentiate: MI300X's 750W TDP demands robust cooling, yet Infinity Fabric scales clusters better than NVLink for distributed training. RTX 3090's 350W suits edge or small-scale inference, trading peak throughput for accessibility.

Live Cloud Pricing

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

MI300X

ProviderGPU ModelVRAMHost SpecsRegionPriceStatusAction
RunPod
RunPod
AMD Instinct MI300X
192GB VRAM
$1.99/GPU/hr
Hot Aisle
Hot Aisle
AMD Instinct MI300X
192GB VRAM
$1.99/GPU/hr
Available
Cirrascale
Cirrascale
8×AMD Instinct MI300X
192GB VRAM
$3.08/GPU/hr
$24.64/hr total (8×)
Crusoe
Crusoe
AMD Instinct MI300X
192GB VRAM
$3.45/GPU/hr
Cirrascale
Cirrascale
8×AMD Instinct MI300X
192GB VRAM
$3.47/GPU/hr
$27.76/hr total (8×)

RTX 3090

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 MI300X

Choose the MI300X for workloads demanding extreme scale: its 192 GB HBM3 VRAM handles full-precision large language models without sharding, unlike the 24 GB limit of RTX 3090. High FP16 at 1307 TFLOPS and FP8 at 2614 TFLOPS accelerate training and inference on datasets over hundreds of gigabytes. Datacenter users benefit from 5300 GB/s bandwidth in multi-node setups via Infinity Fabric.

When to Choose the RTX 3090

Select the RTX 3090 for budget-conscious or prototyping tasks: cloud pricing starts at $0.08 per hour, far below MI300X's $0.50 minimum. Its 35.6 TFLOPS FP16 suffices for fine-tuning models under 24 GB VRAM, and 350W TDP fits consumer hardware. Broader availability across 53 offers supports quick experimentation in Stable Diffusion or small-scale inference.

Use Cases

LLM Training
MI300X

MI300X's 192 GB HBM3 VRAM supports massive models without splitting, and 1307 TFLOPS FP16 speeds training loops. RTX 3090's 24 GB limits scale.

LLM Inference
MI300X

2614 TFLOPS FP8 on MI300X delivers high-throughput serving for large models. Bandwidth of 5300 GB/s handles real-time queries efficiently.

Fine-tuning
RTX 3090

RTX 3090's 24 GB VRAM and 35.6 TFLOPS FP16 suffice for models under 20B parameters at low $0.08 per hour cost. MI300X overkill for this.

Stable Diffusion
RTX 3090

RTX 3090 optimizes consumer graphics with 936 GB/s bandwidth for image generation. Lower 350W TDP and pricing suit creative workflows.

Scientific Computing
MI300X

MI300X's 163 TFLOPS FP32 outperforms RTX 3090's 35.6 TFLOPS for simulations. 192 GB VRAM manages large datasets in HPC.

Frequently Asked Questions

How much VRAM does MI300X have compared to RTX 3090?

MI300X offers 192 GB HBM3 VRAM, enabling large model handling. RTX 3090 provides 24 GB GDDR6X, suitable for smaller tasks. This 8x difference impacts batch sizes in training.

What is the FP16 performance of these GPUs?

MI300X achieves 1307 TFLOPS in FP16 for AI acceleration. RTX 3090 reaches 35.6 TFLOPS, about 37x lower. This gap favors MI300X in deep learning.

Which has higher cloud pricing?

MI300X averages $2.63 per hour across 9 offers, starting at $0.50. RTX 3090 averages $0.41 per hour across 53 offers, from $0.08. RTX 3090 wins on cost.

What is the memory bandwidth difference?

MI300X delivers 5300 GB/s with HBM3. RTX 3090 offers 936 GB/s GDDR6X. Higher bandwidth on MI300X reduces data bottlenecks.

Is MI300X better for LLM inference?

Yes, MI300X's 2614 TFLOPS FP8 and 192 GB VRAM excel in serving large models. RTX 3090's specs limit it to quantized smaller models.

What are the TDPs of these GPUs?

MI300X requires 750W for peak performance. RTX 3090 uses 350W, easier for deployment. Power needs scale with compute demands.

Which is cheaper to rent, the MI300X or the RTX 3090?

Cloud rental prices for both the MI300X 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 MI300X have compared to the RTX 3090?

The MI300X has 192 GB of HBM3 memory. The RTX 3090 has 24 GB of GDDR6X memory.

Can I find MI300X 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 MI300X and the RTX 3090?

The MI300X uses the CDNA 3 architecture (2023) while the RTX 3090 uses Ampere (2020). The MI300X delivers 36.7x the FP16 throughput and 5.7x the memory bandwidth of the RTX 3090.

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