GB300 vs RTX 3090

Blackwell UltravsAmpereUpdated 36 days ago

The GB300 emerges as the superior choice for demanding AI workloads: its 2250 TFLOPS FP16, 288 GB VRAM, and 12000 GB/s bandwidth dominate training and inference over the RTX 3090's 35.6 TFLOPS and 24 GB constraints. Despite lacking live pricing, future deployments justify selection for high-performance needs.

RTX 3090 from $0.20/hr

Specifications Compared

SpecGB300RTX-3090
TDP1400W350W
VRAM288 GB24 GB
Memory TypeHBM3eGDDR6X
ArchitectureBlackwell UltraAmpere
Form FactorsSXMPCIe
InterconnectNVSwitch, NVLinkNVLink
FP8 Performance4,500 TFLOPS
FP16 Performance2,250 TFLOPS35.6 TFLOPS
FP32 Performance90 TFLOPS35.6 TFLOPS
FP64 Performance45 TFLOPS
INT8 Performance4,500 TOPS
Memory Bandwidth12,000 GB/s936 GB/s

Performance Analysis

Memory capacity creates the starkest divide: the GB300's 288 GB HBM3e supports massive batch sizes for training large language models, far exceeding the RTX 3090's 24 GB GDDR6X limit that constrains datasets to smaller scales. Bandwidth amplifies this at 12000 GB/s on the GB300, allowing rapid data movement critical for inference on trillion-parameter models, versus 936 GB/s on the RTX 3090 which bottlenecks high-throughput tasks.

FP16 performance favors the GB300 overwhelmingly at 2250 TFLOPS for mixed-precision training, reducing epochs from days to hours compared to the RTX 3090's 35.6 TFLOPS. The FP32 delta, 90 TFLOPS versus 35.6 TFLOPS, impacts scientific simulations requiring full precision. FP8 at 4500 TFLOPS on the GB300 accelerates inference for quantized models, a capability the RTX 3090 lacks entirely.

Interconnects reflect enterprise focus: NVSwitch and NVLink on the GB300 enable multi-GPU scaling, while the RTX 3090's NVLink suits dual setups but falters in clusters. Higher 1400W TDP on the GB300 demands robust cooling, unlike the efficient 350W RTX 3090.

Live Cloud Pricing

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

RTX 3090

ProviderGPU ModelVRAMHost SpecsRegionPriceStatusAction
TensorDock
TensorDock
NVIDIA GeForce RTX 3090
24GB VRAM
$0.20/GPU/hr
Available
TensorDock
TensorDock
NVIDIA GeForce RTX 3090
24GB VRAM
$0.21/GPU/hr
Available
Vast.ai
Vast.ai
4×NVIDIA GeForce RTX 3090
24GB VRAM
$0.25/GPU/hr
$1.01/hr total (4×)
Available
Vast.ai
Vast.ai
4×NVIDIA GeForce RTX 3090
24GB VRAM
$0.27/GPU/hr
$1.07/hr total (4×)
Available
LeaderGPU
LeaderGPU
8×NVIDIA GeForce RTX 3090
24GB VRAM
$0.29/GPU/hr
$2.29/hr total (8×)
Available

Compare real-time pricing across 25+ providers

When to Choose the GB300

The GB300 excels in hyperscale AI training environments handling models beyond 100 billion parameters, leveraging 288 GB VRAM and 12000 GB/s bandwidth for unprecedented batch sizes. Datacenter operators prioritize its 2250 TFLOPS FP16 and 4500 TFLOPS FP8 for rapid iteration on FP8-quantized inference pipelines.

When to Choose the RTX 3090

Budget-conscious developers select the RTX 3090 for prototyping and fine-tuning smaller models under 10 billion parameters, fitting within 24 GB VRAM at costs from $0.08 per hour. Its 350W TDP and PCIe form factor suit personal workstations or small-scale cloud instances where availability trumps raw power.

Use Cases

LLM Training
GB300

GB300's 288 GB VRAM and 2250 TFLOPS FP16 handle massive datasets and parameters infeasible on RTX 3090's 24 GB limit.

LLM Inference
GB300

4500 TFLOPS FP8 and 12000 GB/s bandwidth enable high-throughput serving; RTX 3090 bottlenecks at 936 GB/s.

Fine-tuning
RTX 3090

RTX 3090 suffices for models under 24 GB with 35.6 TFLOPS FP16 at $0.08 per hour; GB300 overkill for small scales.

Stable Diffusion
RTX 3090

RTX 3090's 24 GB VRAM and 936 GB/s bandwidth support image generation efficiently; low cost across 51 offers.

Scientific Computing
GB300

GB300's 90 TFLOPS FP32 outperforms RTX 3090's 35.6 TFLOPS for precision simulations with NVSwitch scaling.

Frequently Asked Questions

What is the VRAM difference between GB300 and RTX 3090?

The GB300 provides 288 GB HBM3e VRAM, dwarfing the RTX 3090's 24 GB GDDR6X. This enables larger models on GB300 without splitting batches.

How do FP16 performances compare?

GB300 achieves 2250 TFLOPS FP16 versus RTX 3090's 35.6 TFLOPS. Training speeds scale over 60 times faster on GB300.

Is RTX 3090 cheaper in the cloud?

RTX 3090 starts at $0.08 per hour with average $0.41 per hour across 51 offers. GB300 has no live pricing yet.

What architectures power these GPUs?

GB300 uses Blackwell Ultra from 2025; RTX 3090 employs Ampere from 2020. Generational gap yields GB300's superior specs.

Can RTX 3090 use NVLink?

RTX 3090 supports NVLink for dual-GPU setups. GB300 adds NVSwitch for larger clusters.

What are the TDPs?

GB300 requires 1400W TDP in SXM form; RTX 3090 uses 350W in PCIe. Efficiency favors RTX 3090 for small deployments.

Which is cheaper to rent, the GB300 or the RTX 3090?

Cloud rental prices for both the GB300 and RTX 3090 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 3090?

The GB300 has 288 GB of HBM3e memory. The RTX 3090 has 24 GB of GDDR6X memory.

Can I find GB300 and RTX 3090 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 3090?

The GB300 uses the Blackwell Ultra architecture (2025) while the RTX 3090 uses Ampere (2020). The GB300 delivers 63.2x the FP16 throughput and 12.8x the memory bandwidth of the RTX 3090.

GB300 vs RTX 3090: 63.2x FP16 Gap, 288GB vs 24GB | GPUPerHour