B300 SXM6 vs MI300X

Blackwell UltravsCDNA 3Updated 35 days ago

The NVIDIA B300 emerges as the winner for prevalent AI use cases like LLM training and inference. Its 2250 TFLOPS FP16, 288 GB VRAM, and 12000 GB/s bandwidth deliver unmatched scale and speed, justifying the higher $6.44 per hour average cost over the MI300X for performance-critical applications.

B300 SXM6 from $7.39/hrMI300X from $1.99/hr

Specifications Compared

SpecB300MI300X
TDP1200W750W
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 B300's FP16 performance reaches 2250 TFLOPS, exceeding the MI300X's 1307 TFLOPS, which translates to faster neural network training where half-precision computations dominate. In contrast, the MI300X holds an FP32 advantage at 163 TFLOPS over the B300's 90 TFLOPS, benefiting traditional scientific simulations reliant on single-precision arithmetic. FP8 metrics further favor the B300 at 4500 TFLOPS versus 2614 TFLOPS, accelerating inference for quantized large language models. Higher memory bandwidth of 12000 GB/s on the B300 supports larger batch sizes during training, reducing overhead compared to the MI300X's 5300 GB/s. The B300's 288 GB VRAM capacity enables processing models that exceed the MI300X's 192 GB limit without model parallelism. Power draw differs markedly: 1200W TDP for B300 versus 750W for MI300X, impacting cluster density and cooling needs.

Live Cloud Pricing

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

B300 SXM6

ProviderGPU ModelVRAMHost SpecsRegionPriceStatusAction
RunPod
RunPod
NVIDIA B300 SXM6
262GB VRAM
$7.39/GPU/hr
Scaleway
Scaleway
8×NVIDIA B300 SXM6
262GB VRAM
$8.73/GPU/hr
$69.84/hr total (8×)
Available

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 B300 SXM6

Opt for the NVIDIA B300 in scenarios demanding maximum throughput for large-scale AI training or inference. Its 2250 TFLOPS FP16 and 4500 TFLOPS FP8 outperform the MI300X, paired with 288 GB VRAM for handling models over 192 GB. The 12000 GB/s bandwidth sustains high batch sizes in transformer-based workloads. Despite $2.45 per hour starting pricing, it excels where time-to-result trumps cost.

When to Choose the MI300X

Select the AMD MI300X for budget-conscious deployments or FP32-intensive tasks. At $0.50 per hour starting and 750W TDP, it offers better efficiency than the B300's 1200W and $2.45 per hour. The 163 TFLOPS FP32 suits scientific computing, while 192 GB VRAM handles most mid-sized models adequately.

Use Cases

LLM Training
B300 SXM6

The B300's 2250 TFLOPS FP16 and 288 GB HBM3e VRAM enable training larger models with bigger batches than the MI300X's 1307 TFLOPS and 192 GB.

LLM Inference
B300 SXM6

B300 FP8 performance of 4500 TFLOPS and 12000 GB/s bandwidth support high-throughput quantized inference, surpassing MI300X's 2614 TFLOPS.

Fine-tuning
Either

Fine-tuning often fits within 192 GB VRAM of MI300X at lower $0.50 per hour cost, but B300's superior specs accelerate iterations for complex adapters.

Stable Diffusion
B300 SXM6

B300's 2250 TFLOPS FP16 handles diffusion model generation faster, with 288 GB VRAM allowing larger resolutions than MI300X.

Scientific Computing
MI300X

MI300X's 163 TFLOPS FP32 outperforms B300's 90 TFLOPS for simulations, at lower 750W TDP and $2.63 per hour average.

Frequently Asked Questions

When was each architecture released?

Blackwell Ultra for B300 launched in 2025, while CDNA 3 for MI300X dates to 2023. Newer architecture brings B300 optimizations for current AI demands.

Which is cheaper to rent, the B300 or the MI300X?

Cloud rental prices for both the B300 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 B300 have compared to the MI300X?

The B300 has 288 GB of HBM3e memory. The MI300X has 192 GB of HBM3 memory.

Can I find B300 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 B300 and the MI300X?

The B300 uses the Blackwell Ultra architecture (2025) while the MI300X uses CDNA 3 (2023). The B300 delivers 1.7x the FP16 throughput and 2.3x the memory bandwidth of the MI300X.

B300 SXM6 vs MI300X: NVIDIA 288GB vs AMD 192GB | GPUPerHour