B300 SXM6 vs MI355X

Blackwell UltravsCDNA 4Updated 35 days ago

The NVIDIA B300 claims victory for dominant AI workloads like LLM training and inference, thanks to its 12000 GB/s bandwidth enabling larger batches and superior NVLink scaling over MI355X's 8000 GB/s and Infinity Fabric. Availability at $2.45 per hour further solidifies its edge in production environments.

B300 SXM6 from $7.39/hr

Specifications Compared

SpecB300MI355X
TDP1200W750W
VRAM288 GB288 GB
Memory TypeHBM3eHBM3e
ArchitectureBlackwell UltraCDNA 4
Form FactorsSXMOAM
InterconnectNVSwitch, NVLinkInfinity Fabric
FP8 Performance4,500 TFLOPS4,600 TFLOPS
FP16 Performance2,250 TFLOPS2,300 TFLOPS
FP32 Performance90 TFLOPS2300 TFLOPS
FP64 Performance45 TFLOPS72 TFLOPS
INT8 Performance4,500 TOPS4,600 TOPS
Memory Bandwidth12,000 GB/s8,000 GB/s

Performance Analysis

Memory bandwidth emerges as a critical differentiator: the B300's 12000 GB/s enables handling larger batch sizes in training and inference compared to the MI355X's 8000 GB/s, reducing bottlenecks in data movement for models exceeding hundreds of billions of parameters. FP16 performance is nearly identical at 2250 TFLOPS for B300 and 2300 TFLOPS for MI355X, suiting mixed-precision training workflows effectively on both.

FP32 throughput reveals a stark contrast, with MI355X at 2300 TFLOPS vastly outperforming B300's 90 TFLOPS; this favors MI355X for simulation-heavy scientific computing or graphics rendering requiring full precision. FP8 rates of 4500 TFLOPS on B300 and 4600 TFLOPS on MI355X support efficient inference at reduced precision. The B300's 1200W TDP demands robust cooling, while MI355X's 750W enhances density in racks.

In real-world terms, higher bandwidth on B300 accelerates throughput for bandwidth-bound AI workloads, whereas MI355X excels in FP32-dominant scenarios, balancing power efficiency against compute specialization.

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
VERDA
VERDA
NVIDIA B300 SXM6
262GB VRAM
$7.50/GPU/hr
Available
VERDA
VERDA
2×NVIDIA B300 SXM6
262GB VRAM
$7.50/GPU/hr
$15.00/hr total (2×)
Available
VERDA
VERDA
8×NVIDIA B300 SXM6
262GB VRAM
$7.50/GPU/hr
$60.00/hr total (8×)
Available
Scaleway
Scaleway
8×NVIDIA B300 SXM6
262GB VRAM
$8.73/GPU/hr
$69.84/hr total (8×)
Available

Compare real-time pricing across 25+ providers

When to Choose the B300 SXM6

Opt for the NVIDIA B300 in memory-bandwidth constrained environments, such as large-scale LLM training with batch sizes over 1 million tokens, where its 12000 GB/s outperforms the MI355X's 8000 GB/s. NVLink and NVSwitch enable seamless multi-GPU scaling up to thousands of GPUs, ideal for hyperscale clusters. Current availability at $2.45 per hour makes it practical for immediate cloud deployments.

When to Choose the MI355X

Select the AMD Instinct MI355X for FP32-intensive tasks like molecular dynamics simulations, leveraging its 2300 TFLOPS versus B300's 90 TFLOPS. Its 750W TDP versus 1200W allows higher rack density, reducing operational costs in power-limited data centers. OAM form factor suits custom OEM integrations where efficiency trumps peak bandwidth.

Use Cases

LLM Training
B300 SXM6

B300's 12000 GB/s bandwidth supports larger batch sizes critical for training models over 1 trillion parameters, outperforming MI355X's 8000 GB/s.

LLM Inference
B300 SXM6

Higher 12000 GB/s bandwidth on B300 accelerates serving high-concurrency requests with large contexts, despite similar FP8 at 4500 TFLOPS versus 4600 TFLOPS.

Fine-tuning
Either

Comparable FP16 at 2250 TFLOPS and 2300 TFLOPS, plus identical 288 GB VRAM, make both viable for parameter-efficient fine-tuning.

Stable Diffusion
MI355X

MI355X's 2300 TFLOPS FP32 handles diffusion model computations better than B300's 90 TFLOPS, aiding high-resolution image generation.

Scientific Computing
MI355X

MI355X dominates with 2300 TFLOPS FP32 for simulations, far exceeding B300's 90 TFLOPS in precision-dependent workloads.

Frequently Asked Questions

What is the VRAM capacity of B300 and MI355X?

Both GPUs provide 288 GB of HBM3e VRAM, sufficient for models up to 1 trillion parameters. This equality positions them equally for memory capacity in AI tasks.

How do memory bandwidths compare?

B300 delivers 12000 GB/s, doubling MI355X's 8000 GB/s. This gap impacts batch sizes in training, favoring B300 for large-scale workloads.

What are the FP16 performance figures?

B300 achieves 2250 TFLOPS FP16, while MI355X reaches 2300 TFLOPS. The close performance suits mixed-precision training on either GPU.

Which has lower power consumption?

MI355X uses 750W TDP compared to B300's 1200W. Lower TDP enables denser deployments in power-constrained facilities.

Is cloud pricing available for these GPUs?

B300 SXM6 starts at $2.45 per hour, averaging $6.44 per hour across 7 offers. MI355X has no live cloud offers currently.

What interconnects do they use?

B300 employs NVSwitch and NVLink for multi-GPU scaling. MI355X uses Infinity Fabric, suitable for AMD ecosystem clusters.

Which is cheaper to rent, the B300 or the MI355X?

Cloud rental prices for both the B300 and MI355X 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 MI355X?

The B300 has 288 GB of HBM3e memory. The MI355X has 288 GB of HBM3e memory.

Can I find B300 and MI355X 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 MI355X?

The B300 uses the Blackwell Ultra architecture (2025) while the MI355X uses CDNA 4 (2025). The MI355X delivers 1.0x the FP16 throughput and 1.5x the memory bandwidth of the B300.

B300 SXM6 vs MI355X: NVIDIA 288GB vs AMD 288GB | GPUPerHour