Close unused workbooksĪ performance biproduct of the single document interface (SDI) is that each workbook has its own window which needs to be redrawn each time Excel is repainted on your screen. While the engineers at Microsoft obviously thought these ‘improvements’ were great ideas, I’m yet to come across a financial modeler who isn’t mourning the loss of performance that they have caused, so I thought I’d share some performance tips we’ve discovered at Modano that might help mitigate the pain. One of the main reasons for this that the Excel 2016 user interface supports high-resolution displays, and uses a single document interface (SDI), meaning that each workbook opens within its own window rather than them all opening within a single window as they did in Excel 2010. Many of Modano’s clients are making the leap from Excel 2010 to Excel 2016 (I’m going to pretend Excel 2013 never happened, so if you're using Excel 2013 please do yourself a favour and upgrade to Excel 2016 immediately), and noticing that many things feel slower and appear to lag in Excel 2016. Modano Moderator Note: Strikethrough font has been used to indicate parts of this post which are no longer applicable as a result of improvements to performance and stability of Excel since this post was created.