Traditional blockchains are CPU-bound. Realm breaks this bottleneck by offloading heavy cryptographic operations to the GPU.
The CPU Bottleneck
Signature verification is the most computationally expensive part of validating a block. In a traditional blockchain, the CPU processes transactions sequentially (or with limited parallelism). This limits throughput to a few thousand TPS at best.
Massive Parallelism
GPUs are designed for massive parallelism. By batching thousands of transactions and verifying their Dilithium-3 signatures simultaneously on an NVIDIA H100 or even a consumer RTX 4090, we achieve throughputs that are orders of magnitude higher than CPU-based chains.
- Batch Verification: Instead of verifying one signature at a time, we verify 10,000+ in a single CUDA kernel launch.
- Zero-Copy Networking: Using GPUDirect RDMA, transaction data flows directly from the network card to GPU memory, bypassing the CPU entirely.
