According to http://support.microsoft.com/kb/944884 IIS 6 and IIS 7 logs include network time unless response is smaller than 2 kb, does this changed on IIS 8, could not find relevant information.
If not, is there any other way to log time without network time on IIS 8 ?
update :
to clarify, I am allready analyizing IIS logs and I want to monitor time needed for IIS to complete request. It would be enough to get timings for ASP.NET pages, but don't wont to use ASP.NET trace, it seems as an overkill for what I need.