What is the fastest way to create a select tag with 5000 options in IE6?

Question

Usability aside: What is the fastest way to create a select tag with 5'000 option elements in IE6 from JavaScript?

Answer 1

Short test:

• Collecting a innerHTML-string first and inject it to the document: around 300ms
• appending options to an existing select-element using new Option(): around 25 sec

Answer 2

Appending options via DOM methods will cause a reflow/repaint of the screen for every option, slowing it all down. Using innerHTML after building a string (in memory) for your select is much faster (as Dr Molle told). An alternative to both methods would be to create an in memory documentFragment, build your select object in it and finally append it's contents into the exististing DOM.

This aside from the question how a user should handle 5000 options of course (alas, the user isn't programmable ;)