Do I Need a new Viceo Card?

My system is Windows Pro 64 with 24 GB of memory 3 hard drives and a 600 watt PSU.
I have an older GeForce GT 740 2gb card that requires a 4 pin extra power form the PSU. When I use n_Track the Task manager shows that the power read is Very High. When I am using maybe 10 tracks when I change zoom levels ojne or more tracks do not draw until I click on them. I use envelopes to do a great deal of the editing on tracks and sometimes a change will cause the program to quite responding. The Plugins have a lot of graphical display of dials and moving patterns.
I see I can get video cards that do not require the extra power plug and draw from the cards plugin and have 4 gb memory…
Opinions - would a new card help?