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GPU Software for AI: CUDA vs. ROCm

Cem Dilmegani
Cem Dilmegani
updated on Nov 17, 2025

Raw hardware specifications tell only half the story in GPU computing. To measure real-world AI performance, we ran 52 distinct tests comparing AMD’s MI300X with NVIDIA’s H100, H200, and B200 across multi-GPU and high-concurrency scenarios.

While AMD’s MI300X boasts 1,307 TFLOPS compared to NVIDIA’s H100/H200 at 990 TFLOPS, a 32% theoretical advantage, real-world performance is a different picture:

The CUDA gap: When software outperforms hardware

Our analysis introduces the CUDA gap which quantifies how much NVIDIA’s software optimization improves its hardware’s expected performance based on hardware specifications.

A positive score indicates that NVIDIA’s software ecosystem delivers performance gains beyond what raw TFLOPS would predict.

Multi-GPU throughput performance

When scaling to multiple GPUs, the CUDA gap becomes increasingly pronounced:

Analysis: Despite MI300X’s clear theoretical advantage, NVIDIA maintains a growing throughput lead as GPU count increases. CUDA gap scores in the 61–78 range reflect how NVIDIA’s software stack unlocks performance far beyond hardware expectations. See our calculation methodology to understand the calculations.

Note: TFLOPS values use dense computation rates across all GPUs.

Latency analysis

For real-time applications, latency is often more critical than throughput:

At the 8× GPU configuration, the NVIDIA H100 delivers 31.9% lower latency than MI300X.

Practical impact: For interactive AI applications, such as chatbots or real-time inference services, these latency differences directly translate to the quality of the user experience.

Concurrency performance: Real-World SaaS scenarios

The most revealing benchmarks simulate actual production environments with multiple simultaneous users. The results show how concurrency performance changes dramatically based on workload intensity:

Concurrency performance: Analysis

  • At 16 concurrent users, NVIDIA already delivers noticeably higher throughput:
    • H100: +30.8% more throughput
    • H200: +34.4% more throughput
    • B200: +76.5% more throughput
      These results show that NVIDIA outperforms hardware-based expectations even at light workloads, with CUDA gap scores ranging from 34.6 to 66.5.
  • At 128 concurrent users, throughput advantages widen as scheduling and memory-management overheads become more important:
    • H100: +38.7% more throughput
    • H200: +43.0% more throughput
    • B200: +105.3% more throughput
      The B200 more than doubles MI300X throughput at this level, while CUDA gap scores rise to 63.4–75.1.
  • At 512 concurrent users, the software ecosystem becomes the defining performance factor:
    • H100: +67.0% more throughput
    • H200: +37.4% more throughput
    • B200: +77.9% more throughput

Overall, the concurrency benchmark reveals the steepest divergence between AMD and NVIDIA. As real-world workload intensity increases, NVIDIA’s more mature CUDA execution stack continues to scale throughput, while the MI300X plateaus earlier. In SaaS-like environments with many simultaneous requests, software maturity, not raw compute, is the dominant driver of performance.

Feature comparison

NVIDIA CUDA

CUDA (Compute Unified Device Architecture) is NVIDIA’s proprietary parallel computing platform and programming model. Launched in 2006, CUDA has enjoyed nearly two decades of development, optimization, and ecosystem building.

Key advantages:

  • Mature ecosystem: Extensive libraries (cuDNN, cuBLAS, TensorRT) optimized over 18+ years.
  • Developer adoption: Millions of developers trained in CUDA programming.
  • Framework integration: Deep integration with PyTorch, TensorFlow, and all major AI frameworks.
  • Compiler optimizations: Highly sophisticated compilation and runtime optimizations.

Limitations:

  • Vendor lock-in: Proprietary technology tied exclusively to NVIDIA hardware.
  • Closed source: Limited community contributions and transparency.
  • Cost: Market dominance enables higher pricing.

AMD ROCm

ROCm (Radeon Open Compute) is AMD’s open-source software platform for GPU computing, designed as an alternative to CUDA.

Key advantages:

  • Open source: Community-driven development and transparency.
  • Hardware value: Often paired with more powerful hardware on paper (higher TFLOPS).
  • Portability: Designed to work across AMD GPU architectures.
  • Cost-competitive: Generally, more affordable hardware options.

Limitations:

  • Ecosystem maturity: Significantly younger platform (launched 2016).
  • Library optimization: Less optimized libraries and framework integrations.
  • Developer adoption: Smaller developer community and fewer resources.
  • Compatibility issues: Frequent compatibility challenges with popular frameworks.
  • Documentation: Less comprehensive compared to CUDA.

Why does the CUDA gap exist?

1. Library optimization

NVIDIA’s cuDNN, cuBLAS, and TensorRT libraries are meticulously optimized for specific operations. Years of profiling and optimization mean that everyday AI operations run at near-theoretical maximum efficiency.

2. Compiler technology

CUDA’s compiler performs sophisticated optimizations, including:

  • Automatic kernel fusion
  • Memory access pattern optimization
  • Instruction-level parallelism
  • Register allocation strategies

3. Framework integration

PyTorch and TensorFlow have CUDA deeply integrated into their core:

  • Custom CUDA kernels for everyday operations
  • Optimized memory allocators
  • Efficient multi-GPU communication
  • Mature distributed training implementations

4. Ecosystem effects

  • More developers are finding and reporting optimization opportunities
  • Hardware-software co-design advantages
  • Industry partnerships driving optimization priorities
  • Extensive testing and profiling across diverse workloads

Real-world implications

For ML engineers and data scientists

  • Production deployments: CUDA’s performance advantages multiply in production environments with high concurrency
  • Development velocity: Better tooling and documentation accelerate development
  • Troubleshooting: A Mature ecosystem means faster problem resolution

For organizations

  • TCO analysis: Hardware cost savings with AMD may be offset by reduced throughput and increased latency
  • Scaling considerations: CUDA Gap increases with scale, enterprise deployments favor NVIDIA
  • Risk assessment: Vendor lock-in vs. performance trade-offs require careful evaluation

For the industry

  • Competition: AMD’s hardware competitiveness is undermined by the software gap.
  • Innovation: Pressure on AMD to accelerate ROCm development.
  • Open source potential: ROCm’s open nature could eventually mobilize community optimization efforts.

CUDA gap calculation methodology

The CUDA Gap Score is used throughout this article to quantify how much NVIDIA’s real-world performance exceeds (or falls short of) what hardware specifications alone would predict. All throughput, latency, and scalability benchmarks referenced here:

The score is calculated as follows:

AMD’s theoretical TFLOPS advantage

  • Positive → AMD is theoretically more powerful
  • Negative → NVIDIA is theoretically more powerful

NVIDIA’s throughput advantage

Indicates how much more throughput NVIDIA delivers in real-world workloads.

CUDA gap score

Where:

  • Equivalent formulation:

A higher CUDA Gap Score indicates that NVIDIA’s software stack, CUDA, its libraries, compiler optimizations, and execution runtime, delivers performance exceeding hardware-based expectations.

TFLOPS reference values

All TFLOPS figures below are dense (non-sparse) compute rates, aligned with manufacturer specifications and used consistently in all benchmarks:

  • AMD MI300X: 1307.4 TFLOPS
  • NVIDIA H100 SXM: 990 TFLOPS
  • NVIDIA H200 SXM: 990 TFLOPS
  • NVIDIA B200 SXM: 2250 TFLOPS

Dense compute normalization

To ensure a fair comparison:

  • AMD MI300X: Dense rate provided directly
  • NVIDIA H100, H200, B200: Dense rate derived from manufacturer sparse TFLOPS / 2

This ensures that CUDA Gap Scores reflect software impact, not differences in sparse compute acceleration.

💡Conclusion

For AMD to close the CUDA Gap, several strategies emerge:

  1. Library optimization: Focus on optimizing critical operations for popular frameworks.
  2. Developer incentives: Create programs to attract CUDA developers to ROCm.
  3. Partnership strategy: Work directly with framework maintainers for native optimizations.
  4. Documentation investment: Match or exceed CUDA’s documentation quality.
  5. Community building: Leverage open-source advantages to crowdsource optimizations.
  6. Hardware-Software Co-Design: Utilize insights from benchmarks to design ROCm-optimized hardware.

The battle between CUDA and ROCm illustrates a fundamental truth in computing: software ecosystems can be more valuable than raw hardware capabilities. AMD’s MI300X delivers impressive TFLOPS on paper, but NVIDIA’s 18-year investment in CUDA creates performance advantages that defy hardware specifications.

The CUDA Gap Score, ranging from 28.7 to 99.1 across our benchmarks, quantifies this software advantage. It shows that at scale and under real-world conditions, optimized software can deliver performance gains equivalent to having hardware that’s 30-99% more powerful than it actually is.

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Principal Analyst
Cem Dilmegani
Cem Dilmegani
Principal Analyst
Cem has been the principal analyst at AIMultiple since 2017. AIMultiple informs hundreds of thousands of businesses (as per similarWeb) including 55% of Fortune 500 every month.

Cem's work has been cited by leading global publications including Business Insider, Forbes, Washington Post, global firms like Deloitte, HPE and NGOs like World Economic Forum and supranational organizations like European Commission. You can see more reputable companies and resources that referenced AIMultiple.

Throughout his career, Cem served as a tech consultant, tech buyer and tech entrepreneur. He advised enterprises on their technology decisions at McKinsey & Company and Altman Solon for more than a decade. He also published a McKinsey report on digitalization.

He led technology strategy and procurement of a telco while reporting to the CEO. He has also led commercial growth of deep tech company Hypatos that reached a 7 digit annual recurring revenue and a 9 digit valuation from 0 within 2 years. Cem's work in Hypatos was covered by leading technology publications like TechCrunch and Business Insider.

Cem regularly speaks at international technology conferences. He graduated from Bogazici University as a computer engineer and holds an MBA from Columbia Business School.
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