Long spectrum sequences stress attention memory and bandwidth. We benchmark grouped-query attention(GQA) against multi-head attention (MHA) and multi-queryattention (MQA) on FFT-token streams. GQA provides substantialthroughput gains and peak-memory reductions while maintainingaccuracy across token groupings. RF monitoring pipelines often tokenize FFT power spectrainto long sequences for downstream classification or anomalyscoring.