Does more ram and video memory lets u play hd games like GTA 4 maxed out

[RobinGamerMAX999]

Hey Guys,i need help/tips

SYSTEM - Intel Core i3-4130 CPU @ 3.40 GHz
4 GB RAM(2.94 GB USABLE) After i made my video memory to 1 GB
64-Bit System running Windows 7 Ultimate (sp1)
Intel HD Graphics 4400

Graphics Card - Sapphire ATI Radeon HD 5450 2GB DDR3

So my question is i want to play hd games like watchdogs,call of duty,gta 4 etc,can i play these in maxed out settings,if it cant it really doesnt matter to me much atleast i could play it at the lowest settings,so i made my Video Memory to 1 GB and i am left out with 2.94GB usable.i am gonna plug my Graphic card soon,its 2 gb so can i use my video memory with it and could i use both Intel(INTEGRATED) and Radeon(Discrete) at the same time,as far as i know i have a Haswell,its newer than Sandy Bridge so i guess i could use Intel Flexible Display Interface or not.I am also gonna add like 4-8gb ram to my system as sometimes it runs so laggy with low ram.so with all these Ram,Graphics Card 2 gb can i run them in maxed out settings or in low settings(without laggs).This is my new Mini Tower computer,i have just bought it a month ago.does it have the guts and power run this.it would be really helpful if u can answer my question at the earliest.thx a lot

 

[Paul NZ]

May do if the game was 64 bit as well. 32 bit games will probably use so much ram like normal 32 bit programs can

So even if you install 64 GB the game wouldnt use all of it, if it isnt 64 bit

 

[RobinGamerMAX999]

May do if the game was 64 bit as well. 32 bit games will probably use so much ram like normal 32 bit programs can

So even if you install 64 GB the game wouldnt use all of it, if it isnt 64 bit

Anyways Thx for the reply but i still need help,i just dont know what to do to get my games without laggs
and does anybody know the current original price for a DDR3 8 GB RAM