Model Inference Latency Calculator

Model Inference Latency Calculator

Theoretical hardware peak throughput never matches real-world performance - this calculator factors in realistic utilization to estimate actual inference latency.

Effective FLOPs/sec = Hardware Peak FLOPs/sec x Utilization%
Latency = Model FLOPs / Effective FLOPs/sec

Example

A model requiring 1 billion FLOPs per inference, on hardware rated at 10 TFLOPs/sec peak, at 40% real-world utilization:

Effective Throughput = 4 TFLOPs/sec → Latency = 0.25 ms per inference

Why Utilization Is Never 100%

Real-world hardware utilization is always meaningfully below a chip's theoretical peak FLOPs rating - memory bandwidth bottlenecks, kernel launch overhead, and non-ideal operation shapes (that don't map perfectly onto the hardware's parallel compute units) typically limit actual achieved utilization to somewhere in the 20-60% range for many real workloads.

Using This for Capacity Planning

This estimate is useful for rough capacity planning before actually benchmarking a model on target hardware - real measured latency should always be validated with actual profiling once the model and hardware combination is available, since this calculation is only an estimate based on theoretical FLOPs count.