Performance Difference Of Code In Aspx And Cs Files For Showing And Hiding Control Dynamically

I was thinking about the performance when I use code to hide some control in aspx page using delimiters or in cs file. For e.g. If I have a panel and I want it to get shown following some condition, so I can achieve this by two ways

1: Using code in aspx file, something like this

<% if(isAllowed) { %>
<asp:Panel ...></asp:Panel>
<% } %>

2: In the code file, something like this

<asp:Panel ID="pnlMyPanel" Visible="false"></asp:Panel>

And in cs file

if(isAllowed)
pnlMyPanel.Visible=true;

In my view, first way should be good as it will not at all create any Panel in the page. Am I correct here?