Specifications Compared
| Spec | MI355X | RTX-3090 |
|---|---|---|
| TDP | 750W | 350W |
| VRAM | 288 GB | 24 GB |
| Memory Type | HBM3e | GDDR6X |
| Architecture | CDNA 4 | Ampere |
| Form Factors | OAM | PCIe |
| Interconnect | Infinity Fabric | NVLink |
| FP8 Performance | 4,600 TFLOPS | |
| FP16 Performance | 2,300 TFLOPS | 35.6 TFLOPS |
| FP32 Performance | 2300 TFLOPS | 35.6 TFLOPS |
| FP64 Performance | 72 TFLOPS | |
| INT8 Performance | 4,600 TOPS | |
| Memory Bandwidth | 8,000 GB/s | 936 GB/s |
Performance Analysis
Compute disparities define these GPUs: the MI355X's 2300 TFLOPS in FP16 and FP32 enables training large language models sixty-five times faster than the RTX 3090's 35.6 TFLOPS, reducing epoch times dramatically for datasets exceeding twenty-four gigabytes. Equal FP16 and FP32 rates on the MI355X optimize mixed-precision training, whereas the RTX 3090 suits smaller inference runs. The MI355X's 4600 TFLOPS FP8 performance accelerates quantized inference for deployment-scale models. Memory advantages are profound: 288 GB HBM3e versus 24 GB GDDR6X allows batch sizes up to twelve times larger on the MI355X, minimizing out-of-memory errors in transformer training. Its 8000 GB/s bandwidth sustains high utilization during gradient computations, unlike the RTX 3090's 936 GB/s which bottlenecks at scale. Power draw reflects this: 750W TDP for MI355X demands robust cooling, while 350W suits consumer setups.
Live Cloud Pricing
Real-time prices from 25+ providers. Updated every 60 seconds.
RTX 3090
| Provider | GPU Model | VRAM | Host Specs | Region | Price | Status | Action | |
|---|---|---|---|---|---|---|---|---|
 TensorDock | NVIDIA GeForce RTX 3090 24GB VRAM | 24GB | 0 vCPU 0GB RAM | Wilmington, Delaware | $0.20/GPU/hr | Available | ||
TensorDock | NVIDIA GeForce RTX 3090 24GB VRAM | 24GB | 0 vCPU 0GB RAM | Dallas, Texas | $0.21/GPU/hr | Available | ||
 Vast.ai | 4×NVIDIA GeForce RTX 3090 24GB VRAM | 24GB | 32 vCPU 403GB RAM 104GB Storage | Iceland | $0.25/GPU/hr $1.01/hr total (4×) | Available | ||
Vast.ai | 4×NVIDIA GeForce RTX 3090 24GB VRAM | 24GB | 32 vCPU 252GB RAM 1217GB Storage | Finland | $0.27/GPU/hr $1.07/hr total (4×) | Available | ||
 LeaderGPU | 8×NVIDIA GeForce RTX 3090 24GB VRAM | 24GB | 64 vCPU 384GB RAM 2000GB Storage | Netherlands | $0.29/GPU/hr $2.29/hr total (8×) | Available |
When to Choose the MI355X
Opt for the MI355X in hyperscale AI training where models demand over 288 GB VRAM, such as frontier LLMs, leveraging its 2300 TFLOPS FP16 and 8000 GB/s bandwidth for efficient scaling across Infinity Fabric clusters. Datacenter environments with OAM form factors benefit from its CDNA 4 optimizations in scientific simulations requiring 4600 TFLOPS FP8 inference.
When to Choose the RTX 3090
The RTX 3090 excels for prototyping and fine-tuning mid-sized models under 24 GB VRAM, available immediately from $0.08 per hour across fifty-one cloud offers. Consumer workflows, including Stable Diffusion generation or gaming-integrated compute, favor its PCIe compatibility and lower 350W TDP over the unavailable MI355X.
Use Cases
The MI355X's 288 GB HBM3e VRAM and 2300 TFLOPS FP16 handle massive parameter counts without swapping, unlike the RTX 3090's 24 GB limit. Its 8000 GB/s bandwidth supports large batch sizes for faster convergence.
4600 TFLOPS FP8 on the MI355X accelerates high-throughput serving of quantized models exceeding 24 GB. Bandwidth at 8000 GB/s ensures low latency for enterprise deployments.
RTX 3090 suffices for models under 24 GB at $0.08 per hour, but MI355X scales to larger adapters with 288 GB VRAM. Choice depends on model size and budget.
RTX 3090's 35.6 TFLOPS FP16 and PCIe form factor optimize image generation pipelines affordably. Its availability beats the MI355X's lack of live offers.
MI355X's 2300 TFLOPS FP32 and Infinity Fabric excel in parallel simulations needing 288 GB datasets. Superior bandwidth at 8000 GB/s outperforms RTX 3090 by eight and a half times.
Frequently Asked Questions
How much more VRAM does the MI355X have than the RTX 3090?▾
The MI355X provides 288 GB HBM3e, twelve times the RTX 3090's 24 GB GDDR6X. This enables training models too large for the RTX 3090. Datacenter tasks benefit most from the difference.
What is the FP16 performance gap between these GPUs?▾
MI355X delivers 2300 TFLOPS FP16, sixty-five times the RTX 3090's 35.6 TFLOPS. Training accelerates proportionally for compatible workloads. Inference sees similar gains with FP8 at 4600 TFLOPS on MI355X.
Is the RTX 3090 cheaper to rent in the cloud?▾
RTX 3090 rentals start at $0.08 per hour, averaging $0.41 per hour across fifty-one offers. MI355X has no live offers currently. Budget prototyping favors the RTX 3090.
Which GPU has higher memory bandwidth?▾
MI355X achieves 8000 GB/s, eight and a half times the RTX 3090's 936 GB/s. Larger batches process faster without bottlenecks. This impacts training throughput significantly.
What are the power requirements?▾
MI355X demands 750W TDP for datacenter racks, while RTX 3090 uses 350W suitable for desktops. Cooling needs scale accordingly. Efficiency per watt favors MI355X at scale.
Can these GPUs interconnect in clusters?▾
MI355X uses Infinity Fabric for AMD clusters, RTX 3090 employs NVLink for NVIDIA scaling. Multi-GPU training requires matching ecosystems. PCIe on RTX 3090 limits some setups.
Which is cheaper to rent, the MI355X or the RTX 3090?▾
Cloud rental prices for both the MI355X 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 MI355X have compared to the RTX 3090?▾
The MI355X has 288 GB of HBM3e memory. The RTX 3090 has 24 GB of GDDR6X memory.
Can I find MI355X 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 MI355X and the RTX 3090?▾
The MI355X uses the CDNA 4 architecture (2025) while the RTX 3090 uses Ampere (2020). The MI355X delivers 64.6x the FP16 throughput and 8.5x the memory bandwidth of the RTX 3090.