Performance Between Two Measures - How to make the slower one more performant?

AnthonyMCUBI 

Just a question about what you are trying to accomplish.

Doesn't this section of the code:

        CROSSJOIN(
            CALCULATETABLE(
                '*ACM Cylinder History',
                '*ACM Cylinder History'[Date/Time - Last Modified] <> BLANK()
             ),
            DATATABLE(
                "Quantity", INTEGER,
                {  
                    {-1},  
                    {1}
                }  
            ) 
        ),

Always return a 0?  You are summing the [Quantity] which, for every row where the 

'*ACM Cylinder History'[Date/Time - Last Modified] <> BLANK() is both 1 and -1 which makes the SUM 0 right?
When I tested this code 

Running Balance New = 
CALCULATE (
    SUMX ( '*ACM Cylinder History', 1 ),
    '*ACM Cylinder History'[Date/Time - Last Modified] = BLANK (),
    REMOVEFILTERS ( 'Date Dimension' ),
    REMOVEFILTERS ( '*ACM Cylinder History'[Date - Transaction] ),
    FILTER (
        CALCULATETABLE ( RELATEDTABLE ( 'Date Dimension' ), ALL () ),
        ISONORAFTER ( 'Date Dimension'[Date], MAX ( 'Date Dimension'[Date] ), DESC )
    )
)

I get the same results as your original but it is much faster.

A table with the date and just the [Running Balance New] calcs in around 100 - 120 ms