is it worth upgrading from 8400gs to 8800gts

i currently own a pc with the following spec

intel core 2 quad q9300 @ 2.50GHz,
2.00 GB Ram
NVIDIA Geforce 8400GS

i recently perchased Empire Earth 3 but have noticed some lag even when i dramatically reduce the graphics settings in game obviously this has some relevance to the graphics card so my question is is there a need for an upgrade of my graphics card i keep coming across the 8800gts is the upgrade from 8400gs to 8800gts worth it

8400 is a useless card. get the 8800, you will not regret it.

right, get the 512mb one

did this come in a prebuilt system? if so you might want to check the power supply can handle it, but there are less power consuming things that will still RAPE that POS 8400

The only time I saw anyone choose an 8400gs for games is when they simply didn't want to spend more than $40 or so and their integrated video couldn't handle Guitar Hero. You'll do much better with a midrange discrete card than an entry level card.

You'd be better off with a budget 7600gs or something last generation than a recent entry level card, as far as games are concerned. The entry level cards are often geared towards video playback and improving on basic computer tasks like running Vista's 3D Aeroglass.

If you aren't really into games that much, it might be better to just get an 8800gs or something, because it would be a lot cheaper, but probably still just fine for gaming.

But if you want to get serious about gaming, then definitely go with an 8800gts, or wait about a month until the new cards come out.