Sims 3 Specifications

What graphics card does it have ?

No lag is probably not possible with Sims 3 because of the way it's programed and many worlds have huge routing issues but that will bring the best computer to it's knees.

The video card is ATI Radeon HD 4850 , is it good? 
Can i play with these components Sims 3 with all expansion packs & stuff packs + store content on high graphics?

The ATI Radeon HD 4850 is a DX 10.1 and is old for a gaming card. AMD (ATI) now has their version in the r series. With Windows XP gone that makes Vista the oldest supported operating system and Vista SP2 patch bumped DX10 to DX11 and this means you should have a DX11 video card. It should handle TS3 as TS3 is a DX9 game. Performance depends on the dedicated memory used as GDDR5 is faster and improve performance. The 4850 is a PCIe 2.0 chip and therefore slower then today's PCIe 4.0 chips. Looking beyond TS3 it's may be time to upgrade.

one thing I will tell you 8gb ram you may want more ram than that. I have 8gb on my old computer and can not rull all eps without lag. The newer EP's like pets, Island Paradis, Into the future not only need ram but memory and this is per EA. My new computer has 16gb ram and so far no lag on the base game, The more ram the better. The game will run smoother the more ram you have. This game is a ram hog. Video card comes into play too

I can't post a link but google ---mod the sims 3 system requirements  they have a guide what video cards are accepted and other things you will need to run this game