New Post: Writing one sheet with only 100 cells causes using more than 1024 MB !

I'm writing an Yii 1.1.14 app. At a point, user exports to excel. I load in memory 100 values using sql, and my memory_peak_usage is under 128 MB.

Then I start exporting to excel and when at 90% of values written of file, I got a memory exausted for 1024MB. What !?!?

i'm simply using a 2 nested for setting cell value.

Also, I apply some styles, but my script crashed BEFORE i'm starting to apply styles.

What can I do?