GB300 SXM6 vs RTX 4090

Blackwell UltravsAda LovelaceUpdated 35 days ago

The GB300 emerges as the superior choice for most AI and machine learning use cases: its 288 GB VRAM and 2250 TFLOPS FP16 performance enable unprecedented model sizes and speeds unattainable by the RTX 4090. While the RTX 4090 offers affordability at $0.16 per hour, the GB300 dominates in datacenter-scale demands.

RTX 4090 from $0.39/hr

Specifications Compared

SpecGB300RTX-4090
TDP1400W450W
VRAM288 GB24 GB
Memory TypeHBM3eGDDR6X
ArchitectureBlackwell UltraAda Lovelace
Form FactorsSXMPCIe
InterconnectNVSwitch, NVLinkPCIe 4.0
FP8 Performance4,500 TFLOPS660 TFLOPS
FP16 Performance2,250 TFLOPS165 TFLOPS
FP32 Performance90 TFLOPS82.6 TFLOPS
FP64 Performance45 TFLOPS1.3 TFLOPS
INT8 Performance4,500 TOPS660 TOPS
Memory Bandwidth12,000 GB/s1,008 GB/s

Performance Analysis

The GB300's FP16 throughput of 2250 TFLOPS compared to the RTX 4090's 165 TFLOPS translates to over 13 times faster deep learning operations: this benefits neural network training where half-precision computations dominate. FP32 performance shows parity at 90 TFLOPS for the GB300 versus 82.6 TFLOPS for the RTX 4090, supporting graphics rendering and simulations equally well. FP8 metrics underscore inference efficiency, with the GB300's 4500 TFLOPS enabling low-precision serving of large language models at scales unattainable by the RTX 4090's 660 TFLOPS. Memory specifications define real-world limits: the GB300's 288 GB HBM3e VRAM and 12000 GB/s bandwidth accommodate enormous batch sizes in training, preventing out-of-memory errors common with the RTX 4090's 24 GB GDDR6X and 1008 GB/s. Consequently, the GB300 sustains high utilization in multi-GPU clusters via NVLink and NVSwitch, while the RTX 4090 relies on PCIe 4.0 for modest interconnects.

Live Cloud Pricing

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

RTX 4090

ProviderGPU ModelVRAMHost SpecsRegionPriceStatusAction
TensorDock
TensorDock
NVIDIA GeForce RTX 4090
24GB VRAM
$0.39/GPU/hr
Available
Vast.ai
Vast.ai
NVIDIA GeForce RTX 4090
24GB VRAM
$0.40/GPU/hr
Available
TensorDock
TensorDock
NVIDIA GeForce RTX 4090
24GB VRAM
$0.48/GPU/hr
Available
Vast.ai
Vast.ai
NVIDIA GeForce RTX 4090
24GB VRAM
$0.53/GPU/hr
Available
Vast.ai
Vast.ai
4×NVIDIA GeForce RTX 4090
24GB VRAM
$0.67/GPU/hr
$2.67/hr total (4×)
Available

Compare real-time pricing across 25+ providers

When to Choose the GB300 SXM6

Opt for the GB300 in large-scale AI training and inference where models exceed 24 GB VRAM: its 288 GB HBM3e handles trillion-parameter LLMs without partitioning. High memory bandwidth of 12000 GB/s supports massive batch sizes, accelerating convergence in distributed setups via NVLink. Datacenter environments with 1400W TDP tolerance favor the GB300 for sustained peak FP16 performance of 2250 TFLOPS.

When to Choose the RTX 4090

The RTX 4090 suits cost-sensitive, smaller-scale workloads: cloud pricing starts at $0.16 per hour across 110 offers, averaging $0.46 per hour. Its 450W TDP fits consumer or edge deployments, with 24 GB GDDR6X sufficient for fine-tuning models under 20 billion parameters. PCIe 4.0 compatibility enables easy integration where immediate availability trumps raw scale.

Use Cases

LLM Training
GB300 SXM6

The GB300's 288 GB HBM3e VRAM and 2250 TFLOPS FP16 performance handle trillion-parameter models with large batch sizes. The RTX 4090's 24 GB limit forces excessive sharding.

LLM Inference
GB300 SXM6

GB300 FP8 at 4500 TFLOPS and 12000 GB/s bandwidth serve high-throughput quantized models efficiently. RTX 4090's 660 TFLOPS FP8 suits only modest deployments.

Fine-tuning
GB300 SXM6

288 GB VRAM on GB300 supports full-model fine-tuning without gradient checkpointing. RTX 4090 requires parameter-efficient methods due to 24 GB constraint.

Stable Diffusion
RTX 4090

RTX 4090's 24 GB GDDR6X and 82.6 TFLOPS FP32 generate images rapidly at low cost of $0.16 per hour. GB300 overkill for single-user creative tasks.

Scientific Computing
Either

FP32 performance aligns closely at 90 TFLOPS for GB300 and 82.6 TFLOPS for RTX 4090, suiting simulations. Choose RTX 4090 for budget via 110 cloud offers.

Frequently Asked Questions

What is the VRAM difference between GB300 SXM6 and RTX 4090?

The GB300 SXM6 provides 288 GB HBM3e VRAM, enabling massive models. The RTX 4090 offers 24 GB GDDR6X, adequate for medium-scale tasks. This 12-fold gap impacts batch sizes in training.

How do FP16 performances compare?

GB300 SXM6 achieves 2250 TFLOPS in FP16, over 13 times the RTX 4090's 165 TFLOPS. This accelerates deep learning training significantly. Inference benefits similarly from the disparity.

What are the memory bandwidth specs?

GB300 SXM6 delivers 12000 GB/s, preventing bottlenecks in large datasets. RTX 4090 reaches 1008 GB/s, sufficient for prosumer workloads. Higher bandwidth on GB300 boosts utilization.

Is the RTX 4090 cheaper in the cloud?

RTX 4090 cloud pricing starts at $0.16 per hour, averaging $0.46 across 110 offers. GB300 has no live offers currently. This makes RTX 4090 accessible for testing.

What interconnects do they use?

GB300 SXM6 employs NVSwitch and NVLink for multi-GPU scaling. RTX 4090 uses PCIe 4.0 for single-node setups. NVLink enables faster cluster communication.

How do TDPs differ?

GB300 SXM6 requires 1400W TDP for datacenter power supplies. RTX 4090 draws 450W, fitting standard desktops. Higher TDP correlates with GB300's performance lead.

Which is cheaper to rent, the GB300 or the RTX 4090?

Cloud rental prices for both the GB300 and RTX 4090 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 RTX 4090?

The GB300 has 288 GB of HBM3e memory. The RTX 4090 has 24 GB of GDDR6X memory.

Can I find GB300 and RTX 4090 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 RTX 4090?

The GB300 uses the Blackwell Ultra architecture (2025) while the RTX 4090 uses Ada Lovelace (2022). The GB300 delivers 13.6x the FP16 throughput and 11.9x the memory bandwidth of the RTX 4090.

GB300 SXM6 vs RTX 4090: 13.6x FP16 Gap, 288GB vs 24GB | GPUPerHour