The best replacement for throughput is latency.

The best alternatives to throughput are rated as following:
★★★★★  latency
★★★★★  bandwidth
★★★  response time
★★  cycle time
★★  data rate
★  goodput
★  capacity
★  offered load
★  iops
★  throughput
★  output
★  utilization
  processor speed
  io
  packet loss
  lead time
  data transfer rate
  packet size
  download speed
  delay

Your alternative for throughput is not listed? Suggest!
Speaking about throughput, one probably shouldn't forget about firewall.

Other search terms related to throughput and their ratings are:
★★★★★ firewall
You have in mind a companion for throughput and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of throughput in all years. Click on graph for more.
throughput
latency
bandwidth