You can toggle back and forth between SU and V-Ray Frame Buffer via the ‘Window’ menu.
You can also drag the corner of the V-Ray Frame Buffer to re-size (you can’t see my mouse cursor but I grabbed the bottom right corner and adjusted from there):
You can toggle back and forth between SU and V-Ray Frame Buffer via the ‘Window’ menu.
You can also drag the corner of the V-Ray Frame Buffer to re-size (you can’t see my mouse cursor but I grabbed the bottom right corner and adjusted from there):