Looking to sink temperatures from 55°C to anything lower

It's not hard to tell which fan you need. There is this thing called a tape measure that you can use to measure the mm.


If you try to pull in more air than your pushing out you'll create turbulence, so you always want more exhaust than intake.

If you do install intake, just use a small one.

Sounds to me like the answer is a new heatsinkfan. Coolermaster hyper 212+.

From the reseach I've done, the best way to keep air moving properly in a typical chassis is to have at least one 120mm intake fan on the front, and one 120mm exhaust fan on the rear or top. The exhaust fan can be substituted for two 80-90mm fans. The PSU can be used as an exhaust fan if it draws air from within the chassis like a top mounted or OEM system would do. Newer styles with bottom mounted PSU's can either draw air from within or outside of the case depending how you mount it. Those recommendations are only good if you are using a basic system with integrated graphics and a CPU running factory settings and factory heatsink. When you start adding components and your power consumption rises you need to consider moving more air through the case. And generally speaking, the more fans there are, the more turbulant the air flow becomes, which reduces efficiency. So just slapping on fans wherever you find room may not benefit, and instead hamper your efforts.

Intel recommends, for a Thermally Advantaged Chassis, to also have a side vent that allows cool air to be drawn into the case by the movement of air from the front to the rear of the chassis. If your case allows the installation of a side intake fan it will benefit your cooling greatly. The side fan will help keep a graphics card cooler as well. You can also consider upgrading the CPU heatsink. Heatsinks obviously work by soaking up heat generated by the wasted energy of the CPU. Similar to a car's disk brakes, the larger the heat sink, the more effective it is at dissipating heat. But the key to dissipating the heat is getting air to flow through the blades of the heat sink, just like vented brake rotors, and not just swirling around it like an eddy. Heatsinks with integrated fans work best because they forcefeed the heatsink cool air, aka increase convection. But they are only as effective as the temperature of the air already in the case.

Bigger fans move more air than smaller fans, duh! And they typically do it at lower RPM's, which in turn makes them quieter. So if your fan mounts can hold larger fans, go for it. When upgrading fans, try to keep the sizes balanced between intake and exhaust. Using large intake fans, and small exhaust fans can create positive pressure inside the case, while doing the opposite can create negative pressure. It can be debated if a positive air pressure system has any benefits over a neutral system, but almost always does a negative pressure system decrease cooling efficiency.

So with all that said, in regards to your current situation the first thing I would consider is upgrading the heatsink and look into some writeups about thermal interface material, and the proper way to apply them. Less is almost always more, especially with polished surfaces. The whole point of the TIM is to fill in the tiny scratches and bumps on the surfaces of the CPU and heatsink to ensure complete contact of the two... NOT to "glue" them together. The best types of TIM are silver, copper, zinc, and aluminum based. An $8 copper based TIM can be just as effective as a $25 carbon based TIM. Ceramic based is the least effective material. As for the heatsinks themselves, aluminum and copper are 99% of the market and are always a safe bet. Nickel plating keeps the copper from corroding, especially when two unlike metals are in contact. Another factor with heatsinks is the mounting pressure. The more downforce that's applied to the cpu by the heatsink, the better the contact, thus the better the heat conductance. Higher end heatsink kits come with brackets that mount from the backside of the motherboard, increasing contact pressure. Just be carefully when installing them, as too much pressure can damage the cpu or mobo.

Next, I would look at replacing your old worn out fans with newer, and if possible, larger fans. You don't necessarily need to spend $20 per fan. Just compare the mass air flow rates of a few fans to get an idea of cost/perfomance ratio. If your temps don't start dropping significantly after the upgrades, consider installing another intake fan and/or side fan. You should also look at your wire management. If there are a lot of wires weaving there way around the chassis, they may be disrupting air flow and creating more turbulance, especially the old IDE ribbon wires. Try to tuck them to the edges of the case and out of the way. If that still doesnt help, it may be time to look into a new chassis... something with a higher Thermal Design Power rating than what you've currently got.

http://www.intel.com/support/processors/pentium4/sb/cs-008537.htm?wapkw=(thermally+advantaged+chassis)

http://en.wikipedia.org/wiki/Heatsink

http://en.wikipedia.org/wiki/Computer_cooling

That's probably more info than you really wanted, but I'm very enthusiastic about my new computer hobby and like to share the info I've learned

Wow that was a really long reply by mugen.

basically to achieve good CPU or GPU cooling you have to have a good fan, heatsink (with a sufficient area for distributing the heat) and good TIM.

In my experience getting good TIM like thermalright CFIII or Gelid GC-Extreme and the like would reduce temps by at least 5 degrees. The heatsink will give you the best result since you will be spreading the heated area greatly from the stock heatsink provided. This can reduce temps from 15 to 20 C (passive cooling meaning no fan attached). With a fan then you get higher cooling anywhere from 5-10 C. (I know its not too exact but you can get an overall temp reduction of 30 degrees. Like what happened to me). But if your case has horrible airflow then all that i have mentioned will be useless. I have read that the best is trying to keep a balance between the 2 pressures (intake and exhaust is close to each other to avoid turbulence in positive airflow and lack cold air in extreme negative airflow) So make sure you get the right airflow.

Usually fan configurations are
front: intake (usually bigger the better but also check how much air they draw. CMStorm and NZXT have 200mm fans that push quite good but for 120mm you can find quite a lot and for 140mm i prefer the Yateloon d14sh-12 as intake)

Side: intake

Bottom: Intake

Rear: exhaust

Top: exhaust

You've got no place to put a 120 or 140 mm fan.
For not much more money than the cost of a few good fans you can get a new case complete with fans
http://www.newegg.com/Product/Product.aspx?Item=N82E16811129066
That, combined with the HSF reccomended earlier, should do wonders for your temps.

Yes there are, but a 120mm fan (~4.75 inches wide ) won't fit in a 3.5 inch ( ~88mm wide ) bay
Didn't look at the width of the Xion, but I doubt the CM 212+ would fit in it.

The PSU has generaly been moved to the bottom to allow mounting of a radiator or fan at the top. On the bottom its pulling air from outside and spitting it right back out, so it should get better cooling, and a top fan will do more to move air than the PSU did anyway. That being said unless your going to overclock heavily or put a radiator in i don't think it makes much difference.

The antec case is very nice for the price. $45 bucks and free shipping. If your set on the side window with green LED's here's a nice raid max, but its double the price.

The Cooler Master Storm Enforcer is also very nice and in the same price range, but its got red LED's.

I agree on the enforcer or you could also look at the CM Storm Scout. (or Aerocool cases but im not much of a fan but they are quite cheap). The case will really give you great breathing room for your components. Then couple that with awesome HSF for GPU and CPU no problems with cooling anymore (my current setup doesnt go above 30 C above room temp. Room temp is usually 30C)

Take the side panel off, and direct a house fan at the innards.
Assuming that your temps come down to acceptable, you will have confirmed that case cooling is the problem.

The most cost effective solution would be to replace the case.
A great low cost case is the Antec 200, which comes with sufficient cooling fans for only $30 after rebate and free shipping. That is barely the cost of a couple of new fans.
http://www.newegg.com/Product/Product.aspx?Item=N82E16811129074

The stock cooler will do the job. Just make certain that it is installed well. All 4 pushpind must be entirely through the motherboard and locked. There must be no wiggle when installed.
Also, do not apply too much tim, or it will act as an insulator. The purpose is to fill in microscopic air holes in the mating surfaces, and no more. A small drop is all you need. It is hard to use too little.

The Hyper 212 is a very very large cooler. I have never used it, but its 158mm high, or 6.2 inches. There's no way its goine in the APEVIA. The RaidMax or AZZA it MIGHT fit in but I am almost positive you'd have to pull the side panel fans.

This leaves the NZXT, which is only 7.5 inches, but you'll notice it only has one side panel fan, and its dropped down lower. You're also in luck because the hyper 212 and NZXT M59 are both quite poplular. Search the NZXT's comments for "hyper 212" and you've got 8 comments saying the 212 will just barely squeeze in, so it will be tight, but all but one of them gave the case 5 stars.

The Antec recommended earlier is 10 bucks cheaper, and will also take a Hyper 212. Its also slightly better rated, and comes with 4 fans. The NZXT is definitely looks nicer inside though, and has the panel facing hardrives which I like, but it only has a side and rear fan. I'd recommend adding a front one.

BUT for all my rambling first do what geofelt said. If you're not overclocking I'd say get the case, pull the heatsink, clean it and the CPU off thoroughly, reapply your artic silver 5 sparingly, and retry. If your still not satisfied then go for the cooler, you should still have plenty of AS5 to install it.

And one final thought... The case is the one piece of your computer that can last you the longest. I spent $150 on my case in 2003, and am just now considering a new one, when i get around to my next build. Its seen at least 3 different motherboards and 4 CPUS, and I've always had room to work and add parts. If you can scrape up an extra few bucks you might want to consider a case with more features, USB 3.0, front esata, screwless bays, etc. Just my 2 cents. Everyone's needs are different.

To mount the Intel stock cooler properly, place the motherboard on top of the foam or cardboard backing that was packed with it.
It sometimes takes quite a bit of pressure to push down, and you don't want to bend the motherboard.
The 4 push pins should be in the proper position for installation, that is with the pins rotated in the direction of the arrow,(counter clockwise) as far as they can go.
Place the cooler so that all 4 pins are oriented over the holes in the motherboard.
The trick to getting it on is to push down on a diagonal pair of pins at the same time. Then the other pair.
If you do them one at a time, you will not get the cooler on straight.
Lastly, look at the back of the motherboard to verify that all 4 pins are equally through the motherboard, and that the cooler is on firmly.
This last step must be done, which is why the motherboard must be out of the case to do the job.
It is possible to mount the cooler with the motherboard mounted in the case, but you can then never be certain that the push pins are inserted properly.

If you should need to remove the cooler, turn the pins clockwise to unlock them. You will need to clean off the old paste and reapply new if you ever take the cooler off.
Alcohol is fine, the purer the better. I use a paper coffee filter. If you use cloth, the threads can come off, and contaminate the surfaces.

Yes, most anything will do.
You need enough support to keep the motherboard from bending too much, but not so hard to put undue pressure on the components(like a glass tabletop).
A nice flat piece of thick cardboard will do nicely. The motherboard will usually come packed on a pad or whatever, and encloced in antistatic. I find it convenient keep the box to store the manual and other unused parts.