title: Excel/VBA performance
body: <p>I have a certain set of formula in Range("E10001:E20000") which i'd like to copy to Columns("F:CZ") total 1M cells. Options:</p>
  
  <ol>
  <li>Range("E10001:E20000").Copy<br>
  Range("F10001:CZ20000").PasteSpecial xlPasteAll</li>
  <li>Range("F10001:CZ20000").formula = Range("E10001:E20000").formula   </li>
  <li>Range("E10001:CZ20000").fillRight</li>
  <li>Range("E10001:CZ20000").Select<br>
  followed by Ctrl+R in Excel   </li>
  </ol>
  
  <p>At the end, to make the sheet light, i replace formulae with Values, 
  Range("F10001:CZ20000").Value = Range("F10001:CZ20000").Value</p>
  
  <p>What i notice is that Option 4 is way faster than the rest. Can anybody explain the performance penalties in the first 3 options. Note, i'm unfamiliar with time functions and measured physically using seconds clock. </p>