Performance issues using $.ajax async

Performance issues using $.ajax async

Hello,
I am using JQuery on a embedded system which use webkit as browser, i
detect that jquery for asynchronously ajax calls use polling:
3620: var ival = setInterval(onreadystatechange, 13);
instead of:
xhr.onreadystatechange = onreadystatechange;
for my scenary this has performance issues, i like to know why jquery
use the first option when the second could be used.
Thanks and sorry for my english.
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