I am testing check out with 100 configurable items in cart (which is not an uncommon scenario for the live site).
It is so slow that the ajax call in one page check out times out and causes a 500 internal server error after 30 seconds (yes I could extend execution time but that is a separate question).
As per this answer: https://community.magento.com/t5/Magento-1-x-Hosting-Performance/Slow-Submit-Order-at-Check-out/m-p/... I have isolated the issue as being the new order emails are sent with cron after new order submitted.
Is there any way to reduce the execution time here without disabling order emails being sent to the customer (which is obviously important)?
I am just a bit amazed that an application like this doesn't scale whatsoever with a few extra items in the cart.