Are there any hardware experts (or people competent with the aforementioned)?

[LaughingThesaurus]

So here's the deal. I want a computer, and I don't want to buy a prebuilt one. I have no idea how to handle cooling, whether to worry about it, how to find compatible parts, nothing. For the sake of any discussion, assume that I know nothing. I've never ordered parts before, and I don't have the luxury of making any mistakes since I'm on a rather limited budget. Normally I'd be asking this on, say, a slightly more appropriate forum... but we are PC gamers around here so I figure someone's experienced the same sort of deal.

This is a bit important in that I'm kinda basing what I want on the mid-range system. The thing is, I want to drop that price to 700$ at the highest. I don't care about the SSD. I know what those do, and I don't really care about the faster reading times or anything. I'd be spending more time 'inventory managing' such a smallish drive than I'd save by faster loading. The processor also seems really kinda overkill, given that it's a quad-core 3.3 GHz processor... and most games work fine CPU-wise for my system with I think a dual-core 2.7 GHz processor.

What I'd like to do is keep most of what that system has, and pick out a new processor that works for that motherboard and works with everything else. That's what I need, ultimately. I'd also need to know whether all those parts are actually compatible with each other, but I'd like to assume these guys kinda know what they are doing.

In short: Mid-range system. I want to downgrade a few parts, maybe replace that SSD with a 1TB hard drive (though not necessary). I'm looking for a gaming PC in the 600-700$ range. If anyone can help, that'd be awesome.

Edit: I also want to know if I should worry about things being incompatible with older hard drives. Mine are more than adequate but I do want to know for sure if I need to replace them. Everything else on my computer's probably junk and is probably getting replaced, so assume that I don't want any other part of it anymore.

[Cyborg]

You are asking for a small novel on how to build a computer and what's important.

http://lmgtfy.com/?q=How+do+I+build+a+computer

Here is what I would encourage you to do. First of all, get yourself a decent power supply that's not going to destroy your parts after a couple years. This is even more important if you pay your own electric bill. Your next step should be deciding on a motherboard that has the connectors you need for the parts you already own or want to own. For example, USB 3.0 might be really important to you a couple years down the road.

Is cooling important? Hell yes. But you don't need to go all out, a simple $50 aftermarket heatsink/fan will do nicely, not to mention lowering the sound level of your new machine. The biggest reasons your home built computer will suffer is either due to misbehaved cheapo power supplies and heat damage, which occurs over time. That's why laptops are such a bad investment, generally. People expect to play games and pump out high wattage applications in tiny little boxes.  It's technologically challenging to do that without dealing with the heat issue.

For a CPU, nothing short of a i5.  You can cheap it up with an AMD processor, but I've always been scared of compatibility problems, unexplained motherboard phenomena, and I once owned a k6, and it pissed me off. I haven't gotten over it since then.

I hope that helps. It would be nicer if you asked smaller, more specific questions. I have built many machines for myself and my friends, and it's always a night project that ends up in a small informal computer course.

[Volatar]

http://www.reddit.com/r/buildapc/ Is a great resource, particularly all the guide links on the right side.

[Aklyon]

http://pcpartpicker.com/
Not the simplest of places, but its good at giving you plenty of choices. Use Cyborg's/Volatar's link first.

General tips:
AMD is generally cheaper. Both Intel and AMD work more or less the same though, except in motherboard compatibility and a few other details.
SSDs are expensive. If you don't necessarily need one, it'll make it a good bit cheaper to not get it.
If in doubt of compatibility, check and recheck everything. Never hurts to look over your parts list yet again. Especially the motherboard.
An i5 (or the amd equivalent) is pretty much the lowest you should be going, gaming-wise.

Also, to simplify your compatibility question, can you specify what the drives are you want to keep?

[Bossman]

On the cooling issue, if you're going with Intel and don't plan on overclocking, the stock fan that comes with the CPU works well. It comes with a thermal compound pad, so you won't have to mess around with thermal paste. I do this with my i7 and it rarely goes above 55^oC.

Power supply should be no less than 500W, and I'd recommend at least 650W.

If your sound system is basic stereo (no subwoofer), try out the sound system that comes on the motherboard before spending money on an audio card. Higher end motherboards do 5.1 or 7.1 natively, but you probably aren't looking at those.

For your old drives, they should be compatible. SATA ports are backwards compatible, and most motherboards have a (usually awkwardly placed) PATA port for older hard disks and DVD-ROM drives. Floppy drive ports are rare, but who's got a floppy drive in this day and age?

[LaughingThesaurus]

My basic concern is making sure the parts will play nice. I don't really know the general rule on that. Maybe my brother's gonna help me come up with something, but all I know is what he told me. He said, usually all you need to do is make sure your CPU and RAM like your motherboard and that's about the biggest worry. You also need a power supply that is... I don't really know. Not too weak? Not too strong? Somewhere in the middle, at a guess. But, how do you tell what's too weak or too strong? Just add the power usage of all the other parts?

[Hearteater]

I've built my own PC twice, helped my father build his, and am about to build a movie server for all my DVDs/Blu-Rays.  But instead of telling you what to do, let me help you figure out how to do it.  A site I've used a lot in the past is Guru3D.  I'll provide some shopping links to NewEgg, mainly because it's easy to find everything there.  But shop around.  When I built my first computer I bought from four sites over the course of 3 months, watching prices the whole time to get several pieces on sale.  I saved almost $200 on a $1200 computer doing this (~16%).  Watch out for shipping and taxes when comparing.

First, let's begin with the holy trinity: CPU, Motherboard, and Memory.  These pieces are all interdependent.  It is easiest to pick either a CPU or Mother Board you want and then find the other pieces, than find the best of each category and then figure out if they work together.  I'd recommend picking the CPU and going from there.

CPU
First, AMD or Intel, doesn't matter.  I've used AMD for 10 years without a single issue.  At this point there is no difference if you are running Windows, and if you are running *nix then I'll assume you know enough to download the AMD versions of things.  At the present time, Intel chips are generally better, however, when it comes to dollars-to-performance, AMD is generally ahead in the budget $100-200 range.  Both my builds were AMD, but my father's was Intel.  There are going to be pros and cons to both.

Note that AMD has some APUs which are a CPU and graphics card combined.  They are under the name Llano.  You'll have to read reviews to decide if you can go with one of these and skip the graphics card or not.  If you can, you'll probably save about $100 on your final build.  If I recall, this might be a little too low on performance for you, but check them out just in case.  Intel does not have APUs yet (I heard something about Windows 8-only APUs from Intel, but I don't count that).

Besides just checking out reviews and benchmarks, one of my concerns when picking is future upgrade potential.  You want to make sure your CPU plugs into one of the latest sockets (go to bottom of table for latest releases), so you can be certain that new CPUs coming out will fit your mobo, giving you the ability to upgrade your computer in a year or two without having to replace your mobo and RAM. See the Mother Board section for more info.

I strongly recommend you get the Commercial version of a CPU and not the OEM.  The Commercial version should come with a cooling system that will be enough unless you start overclocking.  It also often has warranty advantages in the event it is defective.  The OEM version may not even have installation instructions.  The extra $5-15 is worth it.

Shopping

Mother Board (mobo)

You need a mobo that your CPU can plug in to, and that is determined by the socket type.  AMD and Intel have their own sockets, and they are not in the least compatible.  So there are Intel-only mobos, and AMD-only mobos.  Your mobo choice will also affect what RAM you can use.  It has all the buses (physical pathways) between the CPU and RAM, so some older mobos that might have the right socket for the CPU you pick, might not support the latest and fastest RAM available.  So just be cautious about selecting an older mobo.  But RAM hasn't changed much in the last couple of years so there isn't as many compatibility issues to worry about at present.

When it comes to sockets, for AMD, you want to use either Socket AM3+ or Socket FM1 if you go with a Llano APU.  From Intel go with Socket H2 (also called LGA 1155).  Socket R (also called LGA 2011) is for very high-end stuff, and their CPUs would take up your entire budget.  Also, make sure the mobo size is Standard ATX, or just ATX.  Avoid the micro, extended, or other odd sizes which may require special cases.

Read the mobo reviews.  Read multiple for the mobo you think you want.  There is a lot of stuff beyond basic specs that review can tell you.  Also read what they come with, I've had a mobo that came with every cable you might possibly need, and another that came with barely any (sometimes this is called the Deluxe version).  For the most part the other parts you buy will have the necessary cables, but not always.  Don't be surprised if you find yourself needing a random cable after all the parts come in.

Shopping

Memory (RAM)

At this time, pretty much you can go with DDR3 SDRAM and be fine.  However, RAM does have a speed, so check both your mobo and CPU to see what they can handle.  You need to pick a speed both can handle.  You'll see two speed numbers listed.  One is just a number after the RAM type, like DDR3 2800.  The other is PC3 22400, often shown in parenthesis.  Those are two different values that mean the same speed.  Most RAM will list both numbers, and most CPUs/Mobo will do likewise.  [EDIT:] Faster is better though, so pick the RAM with the highest number that both your mobo and CPU will support.  This can be a compatibility issue for future upgrades if you pick a lower-end CPU that can't handle the faster speeds with the plan to later upgrade the CPU, but the mobo you get could go higher, you'll end up with sub-optimal RAM when you later upgrade.  So if you are picking between two CPUs and one can handle faster RAM, assuming the mobo you plan to get can handle both speeds, consider the higher-end CPU so you can get faster RAM to get the best performance out of your next upgrade.

You're going to read all about latency and other stats, and you'll see RAM can go range from $25-300.  Don't try and interpret how good the RAM is from the stats.  Basically, find a review that lists the memory as reliable with nothing negative to say.  You'll want at least 8gig, and two sticks of 4gig is a very common packaging.  Your mobo should be able to handle 4 sticks total (read the specs on it to be sure) and you can get that for $25-50 a set.  Be aware of whether you are buying a pair of sticks, or a single stick.  Look for "8gig (2x4gig)" compared to "8gig".  For simplicity, get either two or four sticks, and make them all the exact same unless you research carefully.  There are all kinds of timing issues using different sticks can cause, and I don't trust anyone besides an expert to know what's okay.

You aren't going to get crazy performance here, so don't waste a lot of budget on the RAM.  You want reliable and a reasonable price-point.

Shopping

Case

This should be a simple $25-50, unless you've got an existing case you can use.  You want something that can fit a Standard ATX motherboard.  Often if a case is called an ATX case (with nothing in front like Micro, or Extended, or EATX) then it will fit a Standard ATX mobo.  Beyond this you are picking on looks, function (tower, desktop), weight (are you moving this a lot?) and probably most importantly, easy of use.  If you pick a Mini-Tower or other cramped case, you are going to hate assembling your computer.  On the flip side, a huge case can give you problems with cords reaching.  If you've got no other preference, I recommend a Mid-Tower.  Read reviews on the cases, paying attention to those by guys who built a computer and had to deal with any cramping or cabling issues.

Of you've already got a case, determine if it will work for you.  Keep in mind this is a fairly cheap part and not one you want to buy later and move all the guts into.  So either get a new case, or make certain you're ok leaving your new computer in your old case.  Moving everything over is annoying.  There are other parts easier to delay the purchase of than the case.

Shopping

Graphics Card

Once you know what mobo you are getting, check out the Graphics Card connector it has, and start reading reviews to find the card that fits best into your budget.  This is probably the decision you will spend the most time on.  Note that just because you decide you want say a Radeon HD 7000 series, be aware there may be 5+ manufactorers making that card, and the performance of each will be different!  And so will the prices, sometimes by a fair amount.  So make sure you pay attention to manufacturer AND model.

Shopping

Power Supply Unit (PSU)

First, make sure you get an ATX12V PSU, which has the 24-pin connector that the latest mobos use, instead of the old 20-pin.

Besides that, the trickest part of this is figuring out what wattage you need.  There are several calculators on the internet, but keep in mind any future upgrades you plan to make (everything inside the case counts or plugged in via USB, like adding HDDs).  Also keep in mind a PSU doesn't maintain its listed wattage forever, they degrade over time.  So if you pick something that is barely enough, it may fail in 3-5 years.  This also depends a lot on quality of the PSU.  A lot of brand-name expensive stuff is overspecced so you'll never notice the loss, but quite a bit of the cheap no-name stuff is actually underspec and you can get failures very fast.  So consider, if your PSU fails it can destroy every single other component in your computer, and no surge protector can prevent that.  So read reviews carefully, find something name brand, and understand it will cost $75+.

Some PSUs are modular, meaning a lot of their cabling can be removing/attached as needed, which makes for a cleaner case.  Don't worry too much about one-rail versus multiple rails as you won't be putting enough load on the PSU given your budget.  Single rail is less to worry about because you don't need to worry about splitting the power load.

Shopping

Hard Drive (HDD)

Similar to PSUs, read the reviews.  You can get 2TB drives for around $100, and I honestly wouldn't go below 1.5TB.  A SSD is nice, especially for the OS, but they are honestly too expensive for your build so I wouldn't even bother.  Your HDD should be SATA 3.0Gb/s or SATA 6.0Gb/s.  Check out your mobo, which will tell you if it supports 6.0Gb/s.  A 6.0Gb/s HDD will work on a mobo that only does 3.0Gb/s, it just isn't transfering data as fast as it could.

Shopping

Operating System (OS)

Assuming you are going windows, get Windows 7 64-bit Home Premium.  You can go with an OEM version here to save a few bucks, but I've been inclined not to just for support reasons.

Keyboard & Mouse

Lots of choices, but this is one part you can hold off on if you've got existing hardware.  If your old KB&M isn't USB, it probably won't work with modern mobos unless you buy adapters.

Monitor

Similarly, if you have a working monitor, you can save some money here and hold off.  Otherwise, I'd recommend a wide-screen LCD monitor.  Pick something that can handle the max resolution you want, and be sure to read the review first.  Most modern graphics cards should support both DVI and HDMI connections, and so should monitors, so there shouldn't be any compatibility issues unless you try and hook up an old CRT.

If you have any questions, feel free to ask.  I stayed up too late typing this, so I'm sure I missed stuff.

[Bossman]

You also need a power supply that is... I don't really know. Not too weak? Not too strong? Somewhere in the middle, at a guess. But, how do you tell what's too weak or too strong? Just add the power usage of all the other parts?

Add up the maximum power usage of all the parts then multiply that by 1.25 for the minimum. You need a 20% buffer so you aren't stressing the PSU, which shortens the life of the unit. Go for a higher amount if you have future upgrade plans.

[LaughingThesaurus]

Hearteater's post is the best post ever. That basically has everything I could possibly need. Now, to find out if I can make a direct link to that post for any time in the future ever. Thanks a whole bunch for staying up so late to write that. I feel like I should have been more specific so you didn't have to write a thesis paper on computer building essentially.

[Hearteater]

Forgot one minor bit on RAM speed, so I added that in.  And a direct link is here which you can get by clicking on any post's subject.

[keith.lamothe]

I think Hearteater said most everything I would've

Two points I'll add/emphasize:

1) Even if all the ratings match up to indicate the memory will work with the setup: If you put 4 (ymmv) sticks of good-performance memory onto a motherboard, you may need to go into the bios to adjust the voltage that goes to the memory up slightly.  Basically, try it with stock settings and if you see system instability (RAM getting very-slightly-not-enough voltage tends to produce intermittent crashes) that's one place to look and make some careful adjustments.  In general, if you suspect RAM, memtest86+ is a decent program to try.

2) You can get a pretty good idea of a part's reliability by looking at its reviews on newegg; if there aren't a lot of reviews then it doesn't answer a lot, but if there's 600 reviews and it's got 4 or 5 (out of 5) eggs, and the actual text of the first couple pages of reviews is really positive without major complaints about reliability... well, I can say that standard has worked for me in building multiple machines

[Volatar]

Oh, and don't buy ANYTHING manufactured by Ultra. I know it's cheap. I will die on you really, really quick. They only make crap.

[LaughingThesaurus]

I found how to link directly to a post shortly after posting that. Thanks, though!

So I've done some looking, and I'm still more or less fumbling about in the dark shadows of some kind of ignorance. My brother gave some recommendations, and I've done a bit of looking around and came up with something like this. Now, I know it's not everything I'll need, but this is certainly a start I hope, and if I have done well enough so far, that should be the biggest of the compatibility worries out the way.

The mobo says somewhere in the description something about DDR3 (which is a RAM thing, I know that for a fact) then a bunch of numbers. The first number was 2000, so I looked for DDR3 2000, found lots of RAM that fit that description, so I'm kinda assuming that's right. As far as processor goes, I found one that's AMD like the motherboard is. The video card is purely a brother-recommendation, since I have no idea how those work. I could probably afford to upgrade that RAM to 8 GB, but I just want to make sure I got the numbers right.

[Volatar]

I found how to link directly to a post shortly after posting that. Thanks, though!

So I've done some looking, and I'm still more or less fumbling about in the dark shadows of some kind of ignorance. My brother gave some recommendations, and I've done a bit of looking around and came up with something like this. Now, I know it's not everything I'll need, but this is certainly a start I hope, and if I have done well enough so far, that should be the biggest of the compatibility worries out the way.

The mobo says somewhere in the description something about DDR3 (which is a RAM thing, I know that for a fact) then a bunch of numbers. The first number was 2000, so I looked for DDR3 2000, found lots of RAM that fit that description, so I'm kinda assuming that's right. As far as processor goes, I found one that's AMD like the motherboard is. The video card is purely a brother-recommendation, since I have no idea how those work. I could probably afford to upgrade that RAM to 8 GB, but I just want to make sure I got the numbers right.

Dude, I have the same Motherboard, same Graphics Card, same RAM (though I have 8, which I will recommend. Stick with Corsair, they are good). Only thing different about your build is the processor, which looks REALLY nice compared to mine.

You will be happy with that system.

[LaughingThesaurus]

Apparently with that setup I'll definitely need a new power supply. My dad suggests to go with Intel rather than AMD, and suggests the 650 rather than the 550 as video cards go. Any thoughts on that?