question when writing to a file

[bioinfornatics]

Dear,

little question when writing to a file 5 "hello" lines (by 
example)
I would like to know if they are a difference between:

writeln( "hello" ); x5

and:

string[] helloList = [ "hello","hello","hello","hello","hello"];
writeln( helloList.join( newline) );


I mean if one way is more efficient by speed?