Alternative to GPU Inference
FPGA-accelerated inference delivers lower cost, deterministic latency, and an OpenAI-compatible API — without GPUs.
The Problem with GPU Inference
GPU-based inference works well at high batch sizes and for training workloads. But for many production inference scenarios, GPUs have structural inefficiencies:
- Queuing delays — GPU inference servers batch requests for throughput, introducing variable latency. Your P99 latency depends on what other requests are in the queue.
- Underutilization at low batch — A single inference request uses a fraction of an H100's compute capacity, but you still pay for the full GPU's power draw and memory.
- Fixed architecture — GPUs use the same SIMT architecture for every model. A 7B parameter model runs through the same compute fabric as a 405B model, with no hardware-level optimization.
- CUDA lock-in — The GPU inference stack depends on NVIDIA's proprietary CUDA runtime, cuDNN, and TensorRT. This creates vendor dependency and limits optimization flexibility.
- Supply constraints — H100 and H200 GPUs face ongoing supply shortages. Memory (HBM2E) costs are rising, and allocation priority goes to the largest cloud providers.
How FPGA Inference Is Different
FPGAs (Field-Programmable Gate Arrays) are reconfigurable chips. Instead of running software on fixed hardware, you configure the hardware itself to implement the inference pipeline. This means:
Cost: 40-60% Lower
FPGAs deliver 5-20x more tokens per watt than H100/H200 GPUs. Lower power consumption directly translates to lower inference costs. FPGAs also have lower idle power draw — when not processing tokens, energy consumption drops significantly, unlike GPUs that maintain high baseline power.
Based on internal benchmarks and published results from FlightLLM and LoopLynx research.
Latency: Deterministic, Not Variable
GPU inference latency varies based on batching, queuing, and scheduling. FPGA inference pipelines process tokens through dedicated hardware pathways with fixed cycle counts. There is no batch scheduler introducing jitter. Your P50 and P99 latency are effectively the same.
Efficiency: Custom Hardware Per Model
Each model gets a synthesized hardware pipeline optimized for its specific architecture — custom memory hierarchies, tailored attention mechanisms, and arbitrary bit-width arithmetic (not just FP16/INT8/INT4). The FPGA fabric is reconfigured to match the model, not the other way around.
Side-by-Side Comparison
| Dimension | GPU Inference | FPGA Inference (OpenFPGA) |
|---|---|---|
| Cost per token | Baseline | 40-60% lower |
| Latency consistency | Variable (P99 >> P50) | Deterministic (P99 ≈ P50) |
| Energy per token | Baseline | 5-20x more efficient |
| API compatibility | OpenAI-compatible | OpenAI-compatible |
| Model availability | Hundreds of models | Growing (Llama 3.1 8B today) |
| High-batch throughput | Optimized for large batches | Optimized for low batch / real-time |
| Hardware vendor | NVIDIA (CUDA) | Intel (Agilex) |
| Vendor lock-in | CUDA ecosystem | Open hardware, no proprietary runtime |
When to Use FPGA Inference
FPGA inference is the better choice when:
- Latency consistency matters — Real-time applications, interactive agents, trading systems, or any workload where tail latency spikes are unacceptable.
- Cost is a priority — High-volume inference where 40-60% savings compound significantly.
- Low batch sizes — Single-request or small-batch inference where GPUs are underutilized.
- Energy constraints — Edge deployments, sustainability requirements, or data centers with power limits.
- NVIDIA supply risk — Diversifying away from a single hardware vendor.
When to Stay on GPUs
GPUs remain the better choice for:
- Training — FPGAs are not designed for model training. Use GPUs for fine-tuning and training workloads.
- Very large batch inference — At batch sizes of 64+ where GPUs achieve high utilization, the GPU throughput advantage outweighs FPGA efficiency gains.
- Rapid model experimentation — If you change models frequently and need instant availability, GPU providers have broader model catalogs today.
Switching from GPU to FPGA Inference
OpenFPGA uses the same OpenAI-compatible API format as GPU providers. If you currently use OpenAI, Together AI, Groq, Fireworks, or any OpenAI-compatible provider, switching requires changing one line:
Python (OpenAI SDK)
from openai import OpenAI
client = OpenAI(
base_url="https://app.openfpga.ai/api/v1",
api_key="your-openfpga-key"
)
response = client.chat.completions.create(
model="llama-3.1-8b-fpga",
messages=[{"role": "user", "content": "Hello, world"}]
)
print(response.choices[0].message.content)
JavaScript (fetch)
const response = await fetch("https://app.openfpga.ai/api/v1/chat/completions", {
method: "POST",
headers: {
"Content-Type": "application/json",
"Authorization": "Bearer your-openfpga-key"
},
body: JSON.stringify({
model: "llama-3.1-8b-fpga",
messages: [{ role: "user", content: "Hello, world" }]
})
});
const data = await response.json();
console.log(data.choices[0].message.content);
Try FPGA Inference
Same API, different hardware, lower cost. Get an API key and run your first FPGA-accelerated inference.
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