Smarty data upper limit

I am using Smarty to create a table from a big data set (so it can be loaded as excel file) but the table html code get truncated in the middle. What is the upper limited of data feed to Smarty and how can I set it?

From stackoverflow

• Smarty shouldn't have any inherent size limit, since it just gets translated to PHP code.

  Instead, I would check to see if you're running into PHP's memory size limit (edit the memory_limit setting in php.ini) or possibly the execution time limit.