So I was looking into building a new PC, that I'd hack most of mine apart to use in it, probably just the Hardrives, Ram (2x 512 DDR3200) if possible, SoundCard, Power supply (once again if possible), The Box hopefully (if it's big enough). I've never built a PC this far from the ground up yet. Usually I've bought a pre built, then hack in what I wanted. But I wanted to get the most bang for my buck without having to rebuy everything. 1: I know I'll have to buy a new motherboard, if I recal mine doesn't have an AGP port, and I'd assume newer CPU's would plugin to an older board. 2: I really wanted a new graphics card, my old FX5200 is starting to not play most games anymore. I was planning on a nVidia GF8600 GT. But this brings up the annother question of what exactly is SLI and how does it work. My understanding was that it's just 2 cards connected together, but do they automatically share the graphics load and help each other, or does the program using them have to be programmed to use them? I guess I'm asking this guess I want to know if it's worth it to get a SLI compatible board or not? 3: CPU's, I've always had this twisted love of using AMD's with nVidia cards no matter how much people say I'm crazy. No matter what I'm not going to get a ATI I've never had good luck with them. But what is the actuall problem, or is there one, with use AMD with nVidia? and if there is a problem should I go Intel or Celeron? 4: Power supply, from what I've been reading, I've been hearing that newer GPU's and such require extra power? Does that mean I need a seperate power supply for the card or do I just need a bigger power supply for the box? 5: Fan's when buying the above parts new, do they come with fans or do you have to buy your own CPU fan, GPU fan, Power supply fan? and if so are there an recommended requirements to look for? and are box fans nessicery with newer hardware? 6: other than the usual peripherals such as monitor, mouse, keyboard, am I missing anything? thanks in advance.

Wow, careful, seems like you're in for a load of trouble!

1. AGP is totally outdated and I doubt you can find any recent board that still supports it. The replacement for AGP is called PCI-Express, or PCI-e in short (but NOT PCI-X, that's something else!).

CPUs only fit in boards with the exact same socket. There's no backwards compatibility at all. Probably your current board either uses the old Socket 754 or Socket 939. Newer boards use the AM2 socket. If your CPU doesn't have the exact same specification, it won't fit in your board and you can't do a thing about it.

2. Correct, SLI means using two identical graphics cards with SLI capability and connecting them together. It will only provide a moderate performance improvement over one card for any game. You need a mainboard with two PCI-e x16 slots for the second graphics card to fit in, however.

3. Most gamers are using AMD CPUs and quite a lot of them with NVidia cards. Intel has recently regained the "speed king" crown, but everything Intel uses DDR2 RAM, in other words, if you decide to switch to Intel, you can throw away your old RAM. Btw, Celeron IS Intel, it's the weaker budget version of the Pentium line. Just like the Sempron is the weaker budget version of AMD's Athlon line.

4. You might need a bigger power supply for the box, nothing external. If you've got an older PSU, you might have entirely different problems, however. Newer PSUs have 4 extra pins on the ATX jack and an additional 4 pinned jack for providing additional power to your board. Some boards might work without these pins receiving power, depending on the kind of graphics card you use.

5. Power supplies and graphics cards always have fans preinstalled (unless you buy their water cooled variants, but you'd notice by the 4 digit price tag). CPUs are available with and without fans. There are two options available at most online shops: "Boxed" means it's in a nice package together with an original AMD or Intel fan. "Bulk" means you get the CPU in a cheap case without a fan.

Current PC cases are designed to have air flowing through them from the lower front (where, optimally, you hard drives should be located) to the upper back (passing over the CPU and graphics cards) where the hot air will be pushed out by the fan in the power supply (that's why the PSU fan is always blowing air out of the case instead of sucking fresh air in). Having 1 or 2 additional fans isn't wrong for hot summer days, just make sure you don't sabotage the intended airflow or you might end up with a PC that only works with the case opened :)

-Markus-

Wow I really have been out of the loop now, I thought AGP was all the craze cause of it's quicker access to the system memory, and PCI was it's slower counter part.

and one more question about the fans. So if I did get a fan for the box, would it be better to mount it just outside the front bottom, or somewhere inside, maybe near where the CPU and GPU sit?

Thanks for everything else, this'll be a sorta work in progress, so I guess wish me luck.

In my computer I placed the fan in the back, just below the power supply.

Also, PCI and PCI-e are NOT the same. PCI cards will not work in a PCI-e slot, and vice-versa.

Try to see if PC Gamer has any new guides to hardware. I have a few that are several years old and learned quite a bit form them. The main thing to remember is that they don't worry about the cast of hardware to much, but they still include some midrange items.