GPU Upgrade Advice

[thefxgamingrules]

So, I have my PC-
Intel Pentium Dual Core G2020 @ 2.9GHz
4 GB DDR3 1333 MHz
Nvidia GeForce 210 1 GB DDR3
Generic 400w Power Supply
I have been facing poor perfomance from my GPU and plan to upgrade to a nvidia gt 730 (I need a minor GPU upgrade to just get the 210 out)
However, there's a lot of variety out there.
I found these two
Zotac Nvidia GeForce GT 730 4GB GDDR5 64BIT
Zotac Nvidia GeForce GT 730 2GB GDDR5 128BIT
I will be playing mid end games (like Elder Scrolls IV:OBLIVION, GTA 5)
@720P(1366*768) and am fine with low settings. Do I need the 4 GB version? Does the 64/128 Bit make a difference?
Thanks in advance.

 

[romirez]

More Bits = Less FPS drops.
2GB is enough for your (1366*768) mode.