I'm planning to get a good video card

Thanks for the advice. I have little knowledge about video cards. I read many forums and people always compare the performance of nVidia and ATI. I'd better research more before planning of buying a new one.

Honestly, most of those forums are populated by fanboys and number freaks. I wouldn't worry too much: the cards are similar unless you're overclocking and doing other stuff to squeeze the extra 1% out of them and think you're cool. It's like asking "What's a decent, average system spec for a gaming machine for current games?" - you'll end up with a discussion of teraflops, mips and how spending another $4,000 on a pretty blue light is absolutely essential. It's all rather extreme. The best way I've found is to look at a game you'd LOVE to play right now, see what the bare minimum is and add a bit. e.g. If the recommended spec is a 512Mb card, get a 768Mb or 1Gb. But then I don't want to spend $500 on a graphics card that'll be outdated in six months. My current desktop is ten years old now. The machine itself cost me almost $3,000 back in 2001. It wasn't worth it, since I've upgraded the motherboard, the graphics card, the RAM, the drives, the DVD player and absolutely everything else inside the box... except the sound card, the power supply and the ventilation fans! I should've spent a quarter of the original price and upgraded along the way when it was needed. It was a heck of a machine when I built it, though, and for about 2 years after.

Thanks again. I thought there ATI and nVidia has different performance. You're right it depends on the memory of the video card. I also heard that overclocking is only done by professional and advanced users because it might damage your card if you don't know what is overclocking all about.