GPU comparison

B300 SXM6 vs MI300X

Specifications and current cloud pricing, side by side.

Blackwell UltravsCDNA 3Updated 34 days ago

This variant comparison is part of the B300 vs MI300X family comparison.

The B300 SXM6 is the stronger choice for the most common large language model workloads because its 262 GB memory, 8000 GB/s bandwidth and 2250 TFLOPS FP16 dense exceed the MI300X specifications by substantial margins.

B300 SXM6 listed from $0.50/GPU/hrMI300X listed from $0.95/GPU/hr

Right now, from live stock

  • Cheapest right now: B300 SXM6 at $0.50/hr on RunPod

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  • Most providers in stock: B300 SXM6 (1)

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Specifications Compared

SpecB300 SXM6MI300X
TDP1400W750W
VRAM262 GB192 GB
FP4 (dense)13,500 TFLOPSNot published
FP8 (dense)4,500 TFLOPS2,614.9 TFLOPS
Memory TypeHBM3eHBM3
ArchitectureBlackwell UltraCDNA 3
FP16 (dense)2,250 TFLOPS1,307.4 TFLOPS
Form FactorsSXM6OAM
INT8 (dense)187.5 TOPS2,614.9 TOPS
InterconnectNVLink, PCIe 6.0, InfiniBandInfinity Fabric, PCIe 5.0
FP32 Performance75 TFLOPS163.4 TFLOPS
FP64 Performance1.25 TFLOPS81.7 TFLOPS
Memory Bandwidth8,000 GB/s5,300 GB/s
FP4 (with sparsity)18,000 TFLOPSNot published
FP8 (with sparsity)9,000 TFLOPS5,229.8 TFLOPS
FP16 (with sparsity)4,500 TFLOPS2,614.9 TFLOPS
INT8 (with sparsity)375 TOPS5,229.8 TOPS

Performance Analysis

The B300 SXM6 delivers 2250 TFLOPS FP16 dense compared with 1307.4 TFLOPS FP16 dense on the MI300X, producing a 1.72 times advantage in dense matrix operations for training workloads. The same pattern holds for FP16 with sparsity at 4500 TFLOPS versus 2614.9 TFLOPS. Memory bandwidth of 8000 GB/s versus 5300 GB/s permits larger batch sizes during inference and training on the B300 SXM6. FP32 throughput favors the MI300X at 163.4 TFLOPS against 75 TFLOPS yet tensor workloads dominate modern AI pipelines where the B300 SXM6 maintains higher dense and sparsity figures across FP8 and FP4 as well.

Current On-Demand Offers

Cheapest secure on-demand offer per provider that is reported in stock right now, per GPU per hour; multi-GPU instances show the whole-instance price alongside. Deploy opens the DeployGPU console for providers on the platform, otherwise the provider's own site. Stock is rechecked every minute.

B300 SXM6

ProviderRegionGPUsPer GPU / hrInstance / hrDeploy
RunPodglobal1$0.50—Deploy

1 provider in stock, 1 offer. All B300 SXM6 offers, price history and alerts

MI300X

MI300X is not offered on-demand by any provider we track right now. See the MI300X rental page for last-seen listed prices and a price alert.

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When to Choose the B300 SXM6

The B300 SXM6 suits deployments that require maximum memory capacity of 262 GB and highest tensor throughput of 2250 TFLOPS FP16 dense. Its SXM6 form factor and NVLink interconnect support dense multi GPU scaling for large model training. Higher TDP of 1400 W is accepted when absolute performance per GPU takes priority over power draw.

When to Choose the MI300X

The MI300X suits power constrained environments limited to 750 W TDP while still delivering 192 GB memory and 2614.9 TFLOPS FP8 dense. Its OAM form factor and Infinity Fabric interconnect fit existing AMD server platforms focused on energy efficiency. FP32 performance of 163.4 TFLOPS provides an edge in scientific computing codes that rely less on tensor cores.

Use Cases

LLM Training
B300 SXM6

The 262 GB capacity and 2250 TFLOPS FP16 dense support larger models and higher throughput than the 192 GB and 1307.4 TFLOPS on the MI300X.

LLM Inference
B300 SXM6

Higher memory bandwidth of 8000 GB/s enables larger batch sizes during inference compared with 5300 GB/s on the MI300X.

Fine-tuning
B300 SXM6

The 4500 TFLOPS FP16 with sparsity accelerates fine tuning iterations beyond the 2614.9 TFLOPS available on the MI300X.

Stable Diffusion
B300 SXM6

FP8 dense throughput of 4500 TFLOPS exceeds the 2614.9 TFLOPS on the MI300X while 262 GB memory accommodates high resolution image batches.

Scientific Computing
MI300X

FP32 performance of 163.4 TFLOPS surpasses the 75 TFLOPS on the B300 SXM6 for non tensor workloads.

Frequently Asked Questions

How does memory bandwidth differ between these GPUs?▾

The B300 family shares 8000 GB/s bandwidth while the MI300X family shares 5300 GB/s. The difference directly influences achievable batch sizes in training and inference.

What are the FP16 dense figures for each GPU?▾

The B300 family reports 2250 TFLOPS FP16 dense. The MI300X family reports 1307.4 TFLOPS FP16 dense.

Which GPU has the lower TDP rating?▾

The MI300X family carries a 750 W TDP. The B300 family carries a 1400 W TDP.

How do the architectures compare in release year?▾

The B300 uses Blackwell Ultra architecture released in 2025. The MI300X uses CDNA 3 architecture released in 2023.

Which is cheaper to rent, the B300 SXM6 or the MI300X?▾

Cloud rental prices for both the B300 SXM6 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 SXM6 have compared to the MI300X?▾

The B300 SXM6 has 262 GB of HBM3e memory. The MI300X has 192 GB of HBM3 memory.

Can I find B300 SXM6 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 SXM6 and the MI300X?▾

The B300 SXM6 uses the Blackwell Ultra architecture (2025) while the MI300X uses CDNA 3 (2023). The B300 SXM6 delivers 1.7x the dense FP16 throughput (2,250 vs 1,307.4 TFLOPS, both without sparsity) and 1.5x the memory bandwidth of the MI300X.

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How this page is made

  • Specifications come from the NVIDIA, AMD and Intel datasheets for the B300 SXM6 and the MI300X. Dense and sparse throughput are listed separately.
  • Prices and availability are live: every offer shown is an in-stock, on-demand listing from a provider we track, rechecked every minute.
  • The written comparison (overview, performance notes, when to choose each card, verdict, use cases and FAQ) was drafted with an AI model from the specification table above and passed an automated check that rejects any figure not in that table. It was last generated on . It contains no prices; those are always read live.
  • Read how we collect the data, or report an error on this page.

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