At each version, the task "ACAD.exe" is "bigger" but it's normal !
For example with SDI = 1 & with ONE blank DWG open ...
The 32 bits Task MAP 2010 uses about 240 Mb
The 32 bits Task MAP 2014 uses about 330 Mb
Each new version uses about 20-40 Mb MORE compared to previous version !
Of course in the GIS environment, you must be with Win Seven 64 and MAP 201X 64 bits
and 8/12/16 Mb Ram depending on the size of yours documents ...