I am trying to optimize my code as much as possible. I use a lot of partial files like this:
@if (Model.PageMeta.Sidebar == PageMetaSidebar.Small) { Html.RenderPartial("_SmallSidebar"); }
..
..
..
Can someone tell me if there is a performance overhead with this. I understand that Razor views are compiled. Is it the case that when the page is displays there is another disk read to get the data for each of the partial files that I use. If that's the case then how much additional overhead could I expect with for example 5 RenderPartials on my layout page.
There will be no noticable performance hit at all here as the partials are just pulled in on the asp.net web server before streaming the resultant HTML back to the browser. This is not an expensive disk read to do and won't appear any slower than if it was a single cshtml. Obviously partials should be used if the same partial view is reused in many views. If only used in a single view then it's just a matter of clarity splitting it into a separate partials to separate parts of your model into different views.
Note you can also just use:
@Html.Partial("YourPartial")
rather than using RenderPartial. This will look in the local view folder then in shared if not found.