GB300 vs MI300X

Blackwell UltravsCDNA 3Updated 36 days ago

The GB300 emerges as the winner for dominant AI use cases like LLM training and inference. Its 2250 TFLOPS FP16, 4500 TFLOPS FP8, 288 GB VRAM, and 12000 GB/s bandwidth deliver unmatched throughput for large-scale models, despite higher power draw and lack of current pricing.

MI300X from $1.99/hr

Specifications Compared

SpecGB300MI300X
TDP1400W750W
VRAM288 GB192 GB
Memory TypeHBM3eHBM3
ArchitectureBlackwell UltraCDNA 3
Form FactorsSXMOAM
InterconnectNVSwitch, NVLinkInfinity Fabric, PCIe 5.0
FP8 Performance4,500 TFLOPS2,614 TFLOPS
FP16 Performance2,250 TFLOPS1,307 TFLOPS
FP32 Performance90 TFLOPS163 TFLOPS
FP64 Performance45 TFLOPS81.7 TFLOPS
INT8 Performance4,500 TOPS2,614 TOPS
Memory Bandwidth12,000 GB/s5,300 GB/s

Performance Analysis

The GB300 demonstrates superior low-precision performance: its 2250 TFLOPS FP16 and 4500 TFLOPS FP8 significantly outpace the MI300X's 1307 TFLOPS FP16 and 2614 TFLOPS FP8. This delta favors the GB300 for AI training and inference tasks, where models like large language models leverage FP16 and FP8 to accelerate matrix multiplications and reduce memory usage during forward and backward passes.

In FP32 workloads, the MI300X holds an edge with 163 TFLOPS over the GB300's 90 TFLOPS, benefiting simulations or graphics rendering that require higher precision. Memory specifications further differentiate them: the GB300's 288 GB HBM3e and 12000 GB/s bandwidth enable larger batch sizes and longer context lengths in transformer models, minimizing out-of-memory errors compared to the MI300X's 192 GB HBM3 and 5300 GB/s.

Power consumption impacts scalability: the GB300's 1400W TDP demands robust cooling and power infrastructure, potentially limiting density in clusters, while the MI300X's 750W TDP supports higher node counts for cost-sensitive deployments.

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×)

Compare real-time pricing across 25+ providers

When to Choose the GB300

Opt for the GB300 in scenarios demanding peak AI throughput, such as training massive LLMs with billions of parameters. Its 2250 TFLOPS FP16 and 288 GB VRAM handle enormous datasets and extended sequences without fragmentation, outperforming the MI300X's 1307 TFLOPS FP16 and 192 GB VRAM.

The GB300 suits inference at scale too, with 4500 TFLOPS FP8 enabling high-query-per-second rates for real-time applications.

When to Choose the MI300X

Select the MI300X for immediate availability and cost efficiency, with pricing from $0.50 per hour. Its 750W TDP facilitates denser deployments than the GB300's 1400W, ideal for budget-constrained environments.

It excels in FP32-dominant tasks at 163 TFLOPS, such as scientific simulations, where the GB300 trails at 90 TFLOPS.

Use Cases

LLM Training
GB300

The GB300's 2250 TFLOPS FP16 and 288 GB HBM3e VRAM support larger batch sizes and models than the MI300X's 1307 TFLOPS FP16 and 192 GB HBM3.

LLM Inference
GB300

GB300's 4500 TFLOPS FP8 and 12000 GB/s bandwidth enable higher throughput for serving queries compared to MI300X's 2614 TFLOPS FP8 and 5300 GB/s.

Fine-tuning
GB300

Superior memory capacity of 288 GB on GB300 accommodates full model fine-tuning without sharding, unlike MI300X's 192 GB limit.

Stable Diffusion
Either

Both handle diffusion models well, but GB300 offers faster generation via higher FP16, while MI300X provides better availability and lower TDP.

Scientific Computing
MI300X

MI300X's 163 TFLOPS FP32 outperforms GB300's 90 TFLOPS for precision simulations, with lower 750W TDP aiding efficiency.

Frequently Asked Questions

Which GPU has more VRAM?

The GB300 provides 288 GB HBM3e, exceeding the MI300X's 192 GB HBM3. This allows the GB300 to manage larger models without offloading.

How do FP16 performances compare?

GB300 achieves 2250 TFLOPS FP16, nearly double the MI300X's 1307 TFLOPS. This boosts training speed for deep learning workloads.

What is the memory bandwidth difference?

GB300 offers 12000 GB/s, more than twice the MI300X's 5300 GB/s. Higher bandwidth reduces bottlenecks in data-heavy AI tasks.

Which has lower power consumption?

MI300X uses 750W TDP versus GB300's 1400W. This makes MI300X preferable for power-limited clusters.

Is MI300X available for cloud rental?

Yes, MI300X has nine live offers from $0.50 per hour, averaging $2.63 per hour. GB300 currently lacks live offers.

Which excels in FP32 computing?

MI300X delivers 163 TFLOPS FP32, surpassing GB300's 90 TFLOPS. It suits HPC applications needing single-precision accuracy.

Which is cheaper to rent, the GB300 or the MI300X?

Cloud rental prices for both the GB300 and MI300X 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 GB300 have compared to the MI300X?

The GB300 has 288 GB of HBM3e memory. The MI300X has 192 GB of HBM3 memory.

Can I find GB300 and MI300X 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 GB300 and the MI300X?

The GB300 uses the Blackwell Ultra architecture (2025) while the MI300X uses CDNA 3 (2023). The GB300 delivers 1.7x the FP16 throughput and 2.3x the memory bandwidth of the MI300X.

GB300 vs MI300X: NVIDIA 288GB vs AMD 192GB | GPUPerHour