Free Tool
KV Cache & Context Window Calculator.
Every 2× increase in context length doubles your KV cache memory — and halves your effective throughput. See exactly where the cliff is for your model and GPU.
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Architecture: 80 layers · 8 KV heads (GQA) · 128-dim · 140 GB weights (FP16)
KV cache size = 2 × kvHeads × headDim × layers × contextLen × bytesPerElement. Concurrency = floor((totalVRAM − modelWeights − 2GB overhead) ÷ kvPerRequest).
Running long-context workloads in production?
KV cache pressure is one of the leading causes of OOM crashes and GPU underutilization. ParallelIQ Introspect surfaces memory pressure in real time — before it pages you at 2am.