2GB DDR 2 800MHZ vs 3GB DDR2 400MHZ each

Performance-wise,capacity is more important so 3GB DDR2 400MHz will perform better than 2GB DDR2 800MHz especially in apps/games that benefit more than 2GB of RAMs.

It really depends on the OS and applications you run which of the two options would offer the greater performance. Regardless, the first thing you'll need to be certain of is if the memory is configured correctly within the BIOS.

I'm running Windows 7 32bit,but some games still lags although i was watching a video with Crysis running on 2GB DDR2 800MHZ all maxed out on win 7 32bit

In-game "lag" or "stuttering" when there's a lot going on usually has a lot more to do with your graphics card or CPU than it does the amount or speed of your RAM.

I tend to think that 2GB running at twice the speed of 3GB would be the better of the two options, especially when not multi-tasking. (Though, one can easily argue that Windows is a multi-task all by itself.)

True^
The most important factor for gaming is VGA,however newer games benefit from more than 2GB RAM.

Each one of my DDR2 sticks run a frequency of 400MHZ,so i think that would be the problem and i don't think that it would be my CPU cause it's AMD Phenom Quad core 9500 2.2GHZ.

No that's not your problem.RAM speed makes a difference in performance but its not as much as the difference that the capacity makes.(So for example.if you go from 2GB DDR 400 to 2GB DDR2 800,you'll barely see any difference in games, but if you go from 2GB to 4GB(With same speed),you'll notice a difference in games/apps)

Oh okay,now i understand so i'll go for the 4GB DDR2 800 and thanks for the advise.

No problem,hope you enjoy it

Just remember that Windows won't see/use/make accessable all 4GB due to the limitations of 32-bit operating systems. It will likely report somewhere between 3GB and 3.5GB, depending upon the capacity of the video card's memory.

okay,i'm well aware of that.

Just for the sake of asking, what motherboard and CPU are you using? I just want to make sure you get RAM that's designed for both, whether it be two 2GB DDR2-800 sticks, or otherwise.

AMD Phenom Quad core 9500 2.2GHZ and a MCP61PM-HM (Nettle3) motherboard

OK. Funny, there was a guy in another thread I read earlier today with the Nettle2 version.

Two 2GB DDR2-800 should work out just fine. Damn shame such kits still cost twice as much now than they did a year or so ago.

okay thanks for the info.

Can the nvidia geforce 7100 play ghost recon advanced warfighter and ghost recon advanced warfighter 2?

Maybe... The game's requirements state it supports the GeForce 6200-8800.
Source: http://www.ubi.com/US/Games/Info.aspx?pId=5736

The 7100 is about as basic a video processor as you can find. And I mean basic. While it could probably run Warfighter 2, it would likely have to be run at low resolution with low detail levels.

You can buy video cards that kick the living crap out of on-board 7100 chips for as little as $40-60, such as the HD 4650. There are even a few 9600GSO (48 SP models) still available around that price. A few dollars more can get you into a 4670 or 5550. Just about anything would be better than an on-board 7100 chip.