Power: 2 streams and a 2.0 GHz clock pinned by a new checkMaxFreq SETTINGS check (performance governor + scaling_max_freq = fixed clock) take line rate from 80 W to 29.7 W package, qualified 96 s zero-loss; measured on the bench: streams buy scheduling headroom not watts (C1-parked threads, lonelier spinners boost harder), relaxed cpu_dma_latency never reaches deep idle (scheduler spreads wakeups, ~2% residency), offlining E-cores saves 1.7 W and is wire-invisible mid-run, the cliff is TX starvation below 1.6 GHz (1.2 GHz sags to ~18 G, zero errors)

main.go

@@ -105,7 +105,7 @@ func totalRow(elapsed time.Duration, v view, target float64, phy phyDisplay) []s
 }
 
 const (
-	numStreams = 7
+	numStreams = 2
 	batchSize  = 64
 
 	testDriver = "ixgbe"