When building a Gaming PC or looking at one pre-built there are many things you need to consider:
• Chassis/case
• Power supply
• CD/DVD drives
• Hard Drive(s)
• RAM (random access memory)
• Motherboard
• CPU (central processing unit)
• CPU heat sink/fan
• Thermal paste
• Hard drive cable
• CD/DVD drive cable
• Video card (graphics card, GPU)
You also must understand that the Xbox and PS3 have performance power of my old Gaming Rig back in 2006 and even it has better graphics on BF3 than the Xbox360 and PS3.
First thing: YOUR BUDGET!
How much are you willing to spend?
$500 = Low end budget gaming computer.
$850 = Decent/Medium end gaming computer will run most everything on High, some games like BF3, Metro 2033, Crysis 1 & 2 around medium.
$1000 = Good gaming computer, will run most everything on high @ 1080p
$1200 - $1500 = High end multi-monitor gaming computer. Playing Skyrim on 3 screens is fun :)
2nd: Basic knowlegde of the computer:
Look back at the parts, you will need to do some of your own research but all of those parts are necessary for a good gaming computer.
• Chassis/case - Need a good one for ventilation and room for parts.
• Power supply - Needs to be big enough to be able to power all of your components -550W is standard, get a bigger one for the high end rigs.
• CD/DVD drives - Just something you need.
• Hard Drive(s) - Where you stored all your data, theres now SSD which are extremely FAST but are still really pricey. Otherwise get a normal HDD at 7200RPM
• RAM (random access memory) - 8GB is all you need
• Motherboard - VERY IMPORTANT, make sure you get one that can be upgraded and has everything you need on it.
• CPU (central processing unit) - VERY IMPORTANT, I suggest i5-2500k or the new i5-3750k, the i7s arent needed for gaming.
• CPU heat sink/fan - All those components get really hot, you dont want them to melt? Buy some fans and heatsinks to cool everything off.
• Thermal paste - Optional: Cooling paste that keeps your CPU cool when you paste onto the Motherboard
• Hard drive cable - Cables to connect your HDD
• CD/DVD drive cable - Cables to connect your Disc drives
• Video card (graphics card, GPU) - This is what makes games run and will allow you to greatly increase your gaming performance.