DAX running total measures best practice

[dicken]

Hello,

I was looking at different ways of dealing with a running total and I wondered if anyone had any advice on benefits of problems with different methods with regards to efficiency on large data sets which I don't deal with but it would be good to know.

RTM :=
VAR mdate =
    MAX ( dCalendar[Date] )
RETURN
    CALCULATE (
        [Totalunits],
        FILTER ( ALL ( dCalendar[Date] ), dCalendar[Date] <= mdate )
    )

RTMSUMX =
SUMX (
    FILTER ( ALL ( dCalendar[Date] ), dCalendar[Date] <= MAX ( dCalendar[Date] ) ),
    [Totalunits]
)

and

on or after = 
CALCULATE([Tunits],
       FILTER(ALLSELECTED(dCalendar[Date]),
            ISONORAFTER( dCalendar[Date],MAX(dCalendar[Date]),DESC) ))

Richard