Cases and power supplies

[Direhit]

This section is dedicated to cases and power supplies.

[Direhit]

Q: What about acrylic cases?

A: Acrylic cases are a fairly new entry on the market. While there is no real functional advantage to an acrylic case, many users seem to like them because they allow a more unobstructed view of what's inside. Otherwise, it's purely a vanity issue.

Some people are wary of them, since acrylic is a much worse heat conductor than either steel or aluminum, but this isn't really a problem. As long as you have good ventiallation throughout your system, your temperature shouldn't differ from a metal case by more than a couple of degrees.

There are some other disadvantages to an acrylic case, that may discourage one from getting one:

1) Most of them require significant amounts of assembly. Be prepared to take a good amount of time getting one together.

2) Acrylic cases that are cut using conventional methods are going to have rougher edges than those that are laser cut.

3) Acrylic cases are easily dirtied by fingerprints.

4) Acrylic cases, being non-conductive to electricity, can actually trap static electricity charges, and if you touch your motherboard while sending a static electricity discharge through it, you could zap it into data heaven. Always ground yourself when working with these cases.

5) Acrylic cases scratch easily. Although they can withstand more abuse than most metal cases, their clear surfaces are easily marred by things that don't even bother a metal case.

Now, does this mean that you shouldn't get an acrylic case? Not at all. After all, Apple has used acrylic cases for quite a while now, and hasn't reported any serious issues with them.

[Direhit]

Q: Can I combine two separate power supplies to make a single power supply that has the power of both combined?

A: Yes, you can.

http://www.speedy3d.com/articles/cas...p3/index.shtml

shows how you can accomplish this. It is NOT a task that I would recommend that most people undertake. With the cost of good quality power supplies at a very low level, it's better to just get a better power supply.

[Direhit]

Q: How many case fans should I have installed on my system? How should I position them?

A: There is no "one size fits all" solution here. In general, I would recommend that you start out with two case fans. One should be blowing in, and the other one blowing out.

As to placement of the fans, again, there is no "one size fits all" solution either. For starters, though, it's a good bet to try placing an intake fan at the front of the case, and adding the exhaust fan to the rear of the case. Just be sure that the air flow can coordinate with pre-exisiting fans in your system.

[Direhit]

Q: I want to make some modifications to my case, and wanted to know what tools I will need to do this? I want to put additional holes in the sides for cooling fans, etc.

A: For starters, if you are going to be making holes in your case, get a good quality rotary cutting tool. Dremel makes excellent ones, and you can detach the head and replace it with another tool.

When you do this kind of work, wear safety glasses. There's probably going to be a good amount of small metal particles flying around, and you don't want to get them in your eyes. A paper mask might also help you.

Once you make the rough cuts in the case, and have your hole, smooth over the edges with the sanding head using your Dremel tool. Finish this off with a finer grit of sandpaper. If you don't smooth things out, you'll end up cutting your hands whenever you grab that area.

[Direhit]

Q: What about micro-ATX cases? Can I use one for a good gaming machine?

A: I am going to recommend against trying to build a gaming machine around a micro-ATX case. First of all, you are limited to micro-ATX motherboards, and secondly, micro-ATX power supplies are weak, generally topping out at 250 watts.

[Direhit]

Q: Something in my case or power supply is making a grinding noise, that goes away after a while. What is happening here?

A: Usually, when you hear a temporary grinding noise, your fans in your case and / or power supply are due for a cleaning. Take your computer outside, and use some canned air to blast out the dust. As always, wear goggles, and at least a paper filter mask, to prevent yourself from breathing in plastic and metal particulates.

Be sure to use the plastic straw that comes with the canned air, to direct several blasts of gas at the axle on which the fan spins. If you want to be sure, get some Superlube DriFilm (Teflon solubilized in hexanes), and spray around that axle, allowing the hexanes to evaporate. Once the hexanes evaporate quickly, you're left with a dry film of Teflon lube that will help quiet things down.

Do NOT get any of the Teflon spray in your power supply's circuits. This method is only for case fans. For power supplies, stick with canned air only.

[Direhit]

Q: Will an eATX motherboard fit in my standard ATX case?

A: While it will physically fit, the fact that it uses a riser card for its PCI slot / slots will mean that you would either have to not use the riser card, or would have to saw open the slot area in the back of your case. Either situation is impractical.

Do not bother trying to get an eATX motherboard working with your standard ATX case. Do not even bother buying one, unless you have absolutely no plans for expansion.

[Direhit]

Q: On my new power supply, there's an additional connector that has four prongs, arranged in a square-like manner. What is this used for?

A: That connector is an ATX +12V power connector, which supplies the CPU operation voltage. Most newer boards, both AMD and Intel, now have this connector on the board. If you don't have it plugged in, you can't boot.

If your power supply is lacking such a connector, and your motherboard needs such a connection, you can use an adapter to connect one of your standard power connectors that go into your hard drives, into the motherboard.

If you do not plug this in, your motherboard will not boot.

[Janus]

Q: How much power am I using with my Power Supply?

Well I recently stumbled upon this website, that has a general calculator of how many watts are currently in use, and it adds them up by what parts you select.

http://www.jscustompcs.com/power_supply/

[QuakerC4]

RE: "I had to yank out the power cord in my computer to turn it off, and now I can't turn it back on, even though I've plugged it back in correctly."

The switch on the power supply is marked "1" and "0" (one & zero), not "-" & "O" (minus & oh). "1" is "ON", "0" is "OFF".

Two things to note - One: it is generally recommended that you switch the supply "OFF", or unplug the power cord, if the computer is to not be used for an extended period. (Vacation for example)

Two: Under some conditions, for example a short circuit or overload, a good power supply will go into a protective shut-down mode and appear not to work. If so, you may need to switch the power supply "OFF" and back to "ON" (or unplug and re-plug the power cord) to "reset" it back to normal.

[Direhit]

Q: I have a mini-ATX case, and the power supply sits so close to the CPU heat sink, that I'm getting CPU overheating, despite my premium heat sink / cooling fan, etc. What can I do? I don't want to get rid of my case.

A: You need to improve the airflow, and if your power supply is that close to your cooling fan, then you're restricting the air flow.

The easiest way to remedy this problem is to use a low profile heatsink / cooling fan combination. Typically, these are the units made for 1U server / rackmount situations, where there is very little space (similar to your situation above) and they work surprisingly well.

Something like this for an Athlon / Athlon XP CPU (Socket 462 / SocketA):

http://www.newegg.com/app/ViewProduc...roperty&DEPA=1

Or for P4 / Socket 478:

http://www.newegg.com/app/ViewProduc...alog=62&depa=1

[Direhit]

Q: What is this new "BTX" standard for cases?

A: The BTX standard is Intel's latest standard for cases. Supposedly, this will help out the cooling, as it now puts the processor to the rear of the motherboard, instead of up front. There is supposed to be a "wind tunnel" of air flowing over the CPU.

The area where the expansion slots go in an ATX board, and the area in which the ports are located in an ATX board, are reversed in a BTX case. Thus, ATX boards apparently will NOT fit in BTX cases.

Ther RAM slots on a BTX motherboard are also placed on the opposite end of the board, compared to their ATX counterparts.

What does this all mean? For now, this would mean slightly better air flow, resulting in better cooling. Also, the layout of the above mentioned items allows the motherboard manufacturers to make a smaller motherboard.

I do not, however, forsee BTX rendering ATX obselete anytime in the near future, nor do I forsee the new PCI-express slots being only put on BTX motherboards.

At this time, BTX is simply a solution to a problem that's not really much of a problem at all.

[Direhit]

Q: Can I use a BTX power supply with an ATX motherboard?

A: BTX power supplies supposedly have 20 pin connectors, or stepdown connectors, in addition to their BTX connectors, so tentatively, the answer is "yes." Whether the manufacturers decide to keep them the same shape as their ATX counterparts, is still up in the air.

[Direhit]

Q: What kind of power supply do I need? 20 pin or 24 pin? Can I use a 20 pin power supply in a 24 pin motherboard, and vice versa?

A: Just about every motherboard that was produced in the last half year, now uses a 24 pin ATX connector.

In general, you can use a 20 pin power supply in a 24 pin motherboard, as long as it's a decent quality one. Don't, for example, try to plug your cheap Raidmax power supply into a motherboard powering your Core 2 Quad Extreme CPU's. With 24 pin power supplies being plentiful these days, and pretty much the standard, there's really no reason to hold onto that old 20 pin power supply.

You can also use a 24 pin power supply in a 20 pin motherboard. Most 24 pin power supplies can detach the extra four pins from the connector, and you'll be able to attach it just fine.

[Unabomber]

Q: So what kind of power supply do I need these days? Will a 500 watt power supply do the job?

A: Total wattage really isn't a good measure of how much power your power supply can really put out. With today's CPU's and video cards becoming very hungry along the 12 volt rails, your first concern, aside from a power supply using quality components, should be to find a unit that can put out a decent combined maximum amperage on the 12 volt rail.

Some power supplies are listed as dual / triple / quad 12 volt rail units, but you always need to look at the finer print, as to how much *total* amperage on the 12 volt rails that it can really put out.

For example, a Corsair HX620 power supply can generate 18 amps on each of its three 12 volt rails, and does a nice job of combining such rails to generate a maximum of 50 amps on the 12 volt rails.

On the other hand, a Mushkin 550 watt power supply that can supposedly put out 20 amps on each of its dual 12 volt rails, has a maximum combined output of only 28 amps.

(thanks to Johnny Guru for the review)


In general, with today's video cards, you're going to want at least a 30 amp capacity on the 12 volt rails (BFG's 8800 GTS should have at least least 28), although some really hungry cards, such as the GTX280, are going to require at least 42 amps.

Beware of many of the older power supplies, that were listed as "500 watt" units. Many of them simply cannot provide the sheer amount of amperage on the 12 volt rails that are being used by today's devices.


In general, you can't go wrong with the current lineups of Seasonic, Corsair, Antec (earthwatts, Trio, Neo, or Quad), Power PC and Cooling, or Silverstone, as long as the wattage is enough. For example, even if a 380 watt Antec Earthwatts can handle the load that you want to put on it, it's always nice to not be running at the absolute limits of the power supply.

There are many other brands that work just fine; I'm just simply telling you what has worked for me.