Comparing different ways to get minimum of a collection

reductionCompare.scala

case class TestCaseClass(cost: Float, other1: Int, other2: String, other3: String)
val r = new scala.util.Random(31)
val tenkList = 1 to 10000 map (_ => TestCaseClass(r.nextFloat(), r.nextInt, r.alphanumeric.take(3).mkString, ""))
val millionList = 1 to 1000000 map (_ => TestCaseClass(r.nextFloat(), r.nextInt, r.alphanumeric.take(3).mkString, ""))
val tenMillionList = 1 to 10000000 map (_ => TestCaseClass(r.nextFloat(), r.nextInt, r.alphanumeric.take(3).mkString, ""))

def time[R](block: => R): Long = {
  val t0 = System.currentTimeMillis()
  block
  val t1 = System.currentTimeMillis()
  t1 - t0
}

def min(o1: TestCaseClass, o2: TestCaseClass) = if (o1.cost < o2.cost) o1 else o2

println(s"10k: minBy ${time{tenkList.minBy(_.cost)}} and reduce ${time {tenkList.reduce(min)}}")
println(s"1M: minBy ${time{millionList.minBy(_.cost)}} and reduce ${time {millionList.reduce(min)}}")
println(s"10M: minBy ${time{tenMillionList.minBy(_.cost)}} and reduce ${time {tenMillionList.reduce(min)}}")