Is possible to upgrade graphics card RAM?

You cannot upgrade graphics card memory. You have to buy a new card. With AMD/ATI cards, there's no reason to run 2 different models in your computer at the same time for gaming. In order for the cards to be linked together (known as Crossfire for AMD/ATI) so they both provide graphics for your games, they have to be the exact same model number. The cards you mentioned are good for the computer system you have. The 5570 would be the fastest of those.

You can't upgrade the video ram in a graphics card it's best to buy a new one the amd 6000/ 7000 series are the better buy a amd hd 6870 or a amd hd 7750 are good gaming graphic cards to go with than what you mention and very energy efficient , amd athlon are going out might need to upgrade that as well even another motherboard for a am3 processor they are cheaper than the intel's processors

first of all let me tell you that 5450 is rubbish, and a 3 year old laptop has better integrated chip, but anyways, YES you "can" add more ram but only if your a good techie and have the experience of it and also you'd need to write yourself a new BIOS for the new ram config. and honestly for the 5450 its not worth it. i suggest you get something like 6850, or atlest 5770 to be abit future proof but even these two are quite "old" actually but they shold play something like bf3 1080p at low/medium

Your pc is good for Watching HD stuff , surfing internet, playing casual games,etc but when it comes to hardcore gaming your pc will suck. Also there is no possible way to upgrade your GPU. Even 5570 is not good, when it comes to gaming don't look below 5670 or 6670.

Of course, the discrete graphics card installed, the display line re-received on the discrete graphics on it.

You cannot upgrade ur graphic card's RAM..So,if u are looking to buy a new one 5570 is a good card.. Based on ur computer's specs,it's a average to low spec computer in today's standards..

Yes , you can , just replace the old one with whatever you would .

You can't upgrade the video ram in a graphics card it's best to buy a new one the amd 6000/ 7000 series are the better buy a amd hd 6870 or a amd hd 7750 are good gaming graphic cards to go with than what you mention and very energy efficient , amd athlon are going out might need to upgrade that as well even another motherboard for a am3 processor they are cheaper than the intel's processors

You cannot upgrade ur graphic card's RAM..So,if u are looking to buy a new one 5570 is a good card.. Based on ur computer's specs,it's a average to low spec computer in today's standards..