70k.js

const size = 74 * 1024
var packet = { name: 'Paul Serby', email: 'paul.serby@clock.co.uk' }
  , packetSize = JSON.stringify(packet).length
  , count = Math.round(size / packetSize)
  , buffer = []
  , i
  , time = Date.now()
  , bigPacket = Array(size).fill('X')

for (i = 0; i < count; i++) {
  packet.random = Math.random()
  buffer.push(JSON.stringify(packet))
}

for (i = 0; i < count; i++) {
  process.stderr.write(buffer[i])
}

console.log('\n\nSmall packets %d x %d bytes (total: %d bytes) in %dms'
  , count, packetSize, count * packetSize, Date.now() - time)

time = Date.now()
process.stderr.write(JSON.stringify(bigPacket))

console.log('Single write of %d bytes in %dms', size, Date.now() - time)