Hi Raj,
Try these and let me know after doing !
Configure a 1-to-1 allocation of virtual processors to available logical processors for best performance,
Check for network performance ,Test network file transfers (try copying some files between virtual machines and note time taken ),and finally Measure available memory on the Hyper-V host operating system .
I hope you will be able to Optimize Memory Performance and check for the root cause .
Best Regards,
Praveen Srivastava