GPU (Graphics Processing Unit) Architecture
What is a GPU
GPU (Graphics Processing Unit) was originally designed for graphics rendering. Its parallel architecture (thousands of small ALUs) naturally suits AI matrix operations. In 2007, NVIDIA released CUDA, transforming GPUs into GPGPU (General-Purpose GPU), kicking off the AI acceleration era.
Currently 90%+ of AI training and 70%+ of inference runs on GPUs. The CUDA ecosystem is the biggest moat.
GPU vs Other AI Chips
| Dimension | GPU | TPU | ASIC | NPU |
|---|
| General-purpose | Strongest | Medium (Google Cloud only) | Weak | Medium |
| Compute density | High | Extremely high | High | Medium |
| Ecosystem | CUDA dominant | JAX/TF | Vendor-proprietary | Fragmented |
| Programming model | CUDA/OpenCL/SYCL | XLA | Vendor SDK | Vendor SDK |
| Price | High | High (cloud only) | Medium | Medium |
| Best for | General AI / training / inference | Data center training | Inference optimization | Edge/on-device |
Major Vendors
NVIDIA (~90% AI GPU market share)
- Data Center: H100 / H200 / B100 / B200 / B300 / A100
- Inference: L2 / L4 / L40S / T4
- Workstation/Consumer: RTX 4090 / RTX 5090 / RTX 5080 / RTX 6000 Ada
- Edge: Jetson Orin / Jetson Thor
AMD (~5% AI GPU market share)
- Data Center Training: MI250 / MI300X / MI300A / MI325X / MI350
- Ecosystem: ROCm (CUDA alternative, performance lags)
Intel (~3% AI GPU market share)
- Data Center: Intel Max Series (Ponte Vecchio) / Flex Series
- Consumer: Arc series
- Integrated GPU: Meteor Lake / Lunar Lake NPU
Mainstream GPU Spec Comparison
| GPU | Architecture | Memory | FP16 Tensor | TDP | Use Case |
|---|
| NVIDIA B300 Ultra | Blackwell Ultra | 288GB HBM3e | 15 PFLOPS | 1,400W | Top-tier training |
| NVIDIA B200 | Blackwell | 192GB HBM3e | 2.25 PFLOPS | 1,000W | Data center |
| NVIDIA H200 | Hopper | 141GB HBM3e | 1.98 PFLOPS | 700W | Training/inference |
| NVIDIA H100 | Hopper | 80GB HBM3 | 1.98 PFLOPS | 700W | Training/inference |
| NVIDIA RTX 5090 | Blackwell | 32GB GDDR7 | 419 TFLOPS | 575W | Consumer flagship |
| AMD MI355X | CDNA 4 | 288GB HBM3E | 10 PFLOPS | 1,400W | Training |
| AMD MI300X | CDNA 3 | 192GB HBM3 | 1.5 PFLOPS | 750W | Training |
Programming Models
CUDA (NVIDIA)
- CUDA C/C++ — low-level API
- cuDNN — neural network primitives
- cuBLAS — matrix operations
- Triton — Python high-level compiler
- Ecosystem: PyTorch / TensorFlow / JAX / vLLM
ROCm (AMD)
- HIP — CUDA-compatible API
- MIOpen — deep learning library
- Performance: ~70-90% of NVIDIA (workload-dependent)
SYCL / oneAPI (Intel)
- DPC++ — C++ + SYCL
- oneMKL — math library
- Smaller ecosystem, but open source
GPU Use Cases
- ✅ General AI training / inference (mature CUDA ecosystem)
- ✅ LLM training (GPT-3 / LLaMA / Mixtral)
- ✅ Stable Diffusion training
- ✅ Scientific computing (HPC)
- ✅ Multi-workload data center
- ❌ Extreme energy efficiency (use ASIC)
- ❌ Edge/on-device (use NPU)
Selection Guide
| Workload | Recommended GPU |
|---|
| Training GPT-4 class models | B200 / B300 / H200 |
| Training 70B LLM | H100 8-way / MI300X 8-way |
| Training 13B LLM | H100 / A100 |
| Inference 70B+ LLM | H100 NVL / H200 |
| Inference 13B LLM | L40S / L4 |
| Stable Diffusion XL | RTX 4090 / RTX 5090 |
| Edge AI inference | Jetson Orin / Thor |
| HPC + AI joint | MI300A / H100 |
Detailed Product Pages
NVIDIA Data Center (H Series / A Series)
NVIDIA Blackwell (B Series)
- NVIDIA Vera Rubin R200 - 6-chip CoWoS-L package, 288GB HBM4 22 TB/s, 50 PFLOPS FP4 sparse, ConnectX-9 28.8 TB/s
- Rubin NVL72 (1 rack): 72×R200 + 36×Vera, 1.4 EFLOPS FP4 sparse
- Rubin NVL576 (8 racks): 576×R200 + 288×Vera, 28.8 EFLOPS FP4 sparse, 1.1 MW per room
NVIDIA Inference / Edge
AMD
- AMD MI210 - CDNA 2 64GB HBM2e 22.6 TF FP64 PCIe, preferred for Europe's LUMI supercomputer
- AMD MI250 - CDNA 2 128GB HBM2e
- AMD MI300X - CDNA 3 192GB HBM3 5.3 TB/s
- AMD MI300A - CDNA 3 + Zen 4 APU 128GB HBM3
- AMD MI325X - 256GB HBM3e 6 TB/s 1.3 PF FP8
- AMD MI355X - 288GB HBM3E 8 TB/s 4.6 PF FP8 UALoF 600 GB/s
- AMD MI350 - CDNA 4 288GB HBM3E
- AMD MI400 - CDNA Next 432GB HBM4 40 PF FP4 dense, Helios 72-GPU rack
Intel