Specifications Compared
| Spec | GB300 | MI300X |
|---|---|---|
| TDP | 1400W | 750W |
| VRAM | 288 GB | 192 GB |
| Memory Type | HBM3e | HBM3 |
| Architecture | Blackwell Ultra | CDNA 3 |
| Form Factors | SXM | OAM |
| Interconnect | NVSwitch, NVLink | Infinity Fabric, PCIe 5.0 |
| FP8 Performance | 4,500 TFLOPS | 2,614 TFLOPS |
| FP16 Performance | 2,250 TFLOPS | 1,307 TFLOPS |
| FP32 Performance | 90 TFLOPS | 163 TFLOPS |
| FP64 Performance | 45 TFLOPS | 81.7 TFLOPS |
| INT8 Performance | 4,500 TOPS | 2,614 TOPS |
| Memory Bandwidth | 12,000 GB/s | 5,300 GB/s |
Performance Analysis
The GB300's FP16 performance of 2250 TFLOPS significantly exceeds the MI300X's 1307 TFLOPS, accelerating deep learning training where mixed-precision computations dominate. This gap extends to FP8 at 4500 TFLOPS versus 2614 TFLOPS, favoring GB300 for efficient large language model inference. Conversely, MI300X leads in FP32 with 163 TFLOPS against GB300's 90 TFLOPS, benefiting traditional simulations or scientific applications requiring single-precision accuracy.
Memory bandwidth represents a key disparity: GB300's 12000 GB/s versus MI300X's 5300 GB/s enables larger batch sizes in training, reducing iterations and wall-clock time for datasets fitting within 288 GB VRAM compared to 192 GB. Higher VRAM on GB300 supports longer context lengths in transformers without model sharding.
Power efficiency varies, with MI300X's 750W TDP allowing denser racks than GB300's 1400W, impacting total cost of ownership in deployed clusters.
Live Cloud Pricing
Real-time prices from 25+ providers. Updated every 60 seconds.
MI300X
| Provider | GPU Model | VRAM | Host Specs | Region | Price | Status | Action | |
|---|---|---|---|---|---|---|---|---|
 RunPod | AMD Instinct MI300X 192GB VRAM | 192GB | 24 vCPU 256GB RAM | 🌍global | $1.99/GPU/hr | |||
 Hot Aisle | AMD Instinct MI300X 192GB VRAM | 192GB | 8 vCPU 224GB RAM 12288GB Storage | Michigan | $1.99/GPU/hr | Available | ||
 Cirrascale | 8×AMD Instinct MI300X 192GB VRAM | 192GB | 192 vCPU 2355GB RAM 44538GB Storage | United States | $3.08/GPU/hr $24.64/hr total (8×) | |||
 Crusoe | AMD Instinct MI300X 192GB VRAM | 192GB | 0 vCPU 0GB RAM | United States | $3.45/GPU/hr | |||
Cirrascale | 8×AMD Instinct MI300X 192GB VRAM | 192GB | 192 vCPU 2355GB RAM 44538GB Storage | United States | $3.47/GPU/hr $27.76/hr total (8×) |
When to Choose the GB300 SXM6
Opt for the NVIDIA GB300 SXM6 in scenarios demanding extreme scale, such as training models over 192 GB in size, where its 288 GB HBM3e VRAM prevents fragmentation. The 12000 GB/s bandwidth sustains high throughput for massive parallel inference at 4500 TFLOPS FP8. NVLink and NVSwitch interconnects excel in multi-GPU setups for frontier research.
Future deployments planning for 2025 benefit from GB300's Blackwell Ultra architecture, outpacing CDNA 3 in AI-specific precisions.
When to Choose the MI300X
Select the AMD Instinct MI300X for immediate availability and cloud deployment, with pricing from $0.50 per hour averaging $2.63 per hour across nine offers. Its 750W TDP supports higher rack density than 1400W alternatives. Superior FP32 performance at 163 TFLOPS suits HPC tasks like fluid dynamics.
Infinity Fabric and PCIe 5.0 provide flexible scaling in current infrastructures without waiting for 2025 releases.
Use Cases
GB300's 2250 TFLOPS FP16 and 288 GB HBM3e VRAM handle massive datasets and long sequences better than MI300X's 1307 TFLOPS and 192 GB.
FP8 performance at 4500 TFLOPS on GB300 accelerates high-volume serving with 12000 GB/s bandwidth, surpassing MI300X's 2614 TFLOPS.
Higher memory capacity of 288 GB on GB300 supports larger batch sizes during fine-tuning compared to 192 GB on MI300X.
Both GPUs manage image generation workloads effectively, though GB300's bandwidth provides faster iterations; MI300X suffices for current needs at lower cost.
MI300X's 163 TFLOPS FP32 outperforms GB300's 90 TFLOPS for precision-heavy simulations like molecular dynamics.
Frequently Asked Questions
Which GPU has more VRAM?▾
The GB300 offers 288 GB HBM3e VRAM, exceeding MI300X's 192 GB HBM3. This advantage allows GB300 to load larger models without sharding. Memory bandwidth follows suit at 12000 GB/s for GB300 versus 5300 GB/s.
What are the FP16 performance differences?▾
GB300 delivers 2250 TFLOPS FP16, more than double MI300X's 1307 TFLOPS. This boosts training speed for neural networks. FP8 shows similar dominance at 4500 TFLOPS versus 2614 TFLOPS.
Is the GB300 available now?▾
No live cloud offers exist for GB300, as it launches in 2025 on Blackwell Ultra. MI300X is available from $0.50 per hour, averaging $2.63 per hour. Choose MI300X for immediate use.
How do TDPs compare?▾
MI300X consumes 750W TDP, half of GB300's 1400W. Lower power enables denser deployments for MI300X. This impacts cooling and electricity costs in clusters.
What interconnects do they use?▾
GB300 employs NVSwitch and NVLink for high-speed multi-GPU communication. MI300X uses Infinity Fabric and PCIe 5.0. NVLink suits tightly coupled AI scaling.
Which is better for FP32 workloads?▾
MI300X provides 163 TFLOPS FP32, surpassing GB300's 90 TFLOPS. This favors MI300X in scientific computing requiring single precision. AI tasks lean toward GB300's low-precision strengths.
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.