ASP .Net 4.0 app virtual memory increases 50% when .Net 4.5 installed

Question

I have an ASP .Net application running on .Net 4.0.

After deploying an ASP .Net MVC application that uses .Net 4.5, along with the .Net 4.5 redistrbutable, virtual memory consumption of the original application increased by more than 50% (in very rough numbers from around 6GB to around 10GB).

The virtual memory is grabbed early in the run the amount remains stable - not like it's a leak.

When the MVC application was removed, but .Net 4.5 remained, there was (as expected) no change in the first application's virtual memory consumption - it remained higher.

Once the .Net 4.5 was also removed and .Net 4.0 was re-installed, the original application's virtual memory consumption returned to prior levels.

The original application uses Entity Framework extensively. So, I'm wondering if that's a factor.

Are there any known differences in .Net 4.5 that would make this dramatic change in the amount of virtual memory used expected?

Answer 1

Applying latest Windows patches (as of 2/2014) and upgrading to .Net 4.5.1 appears to address this problem.