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Water Cooling For Dummies

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Feb 18, 2010
Water cooling for dummies

1. Water Blocks

CPU water blocks -

Cpu water blocks come in different sizes and materials, but they all perform the same function cooling the CPU. Virtually all modern CPU blocks perform about the same (some slightly better than others). Some blocks have more restriction than others, but with most modern pumps this wont be an issue. So the choice of what block comes down to what you can spend, and what looks visually pleasing to you.

GPU water blocks -

GPU water blocks come in 2 different styles.

The first being a full cover water block. This block covers the entire card, and cools the core, memory, and all other components on the pc board. This is a popular method for water cooling GPU's because it offers the best performance,looks good, and can use SLI fittings to run the blocks in parallel to supply each card with the same temperature water. These blocks are usually made for 1 card, and 1 card only. Which means when you upgrade cards you will have to buy new blocks for the new cards.

The second kind of GPU water block is a universal water block. These are designed to be used on virtually any GPU made by using an adapter (similar to a CPU block). There are pro's and con's to using this kind of block. They are "universal", so when you upgrade they will/should fit your new card. But the con is that they don't cool the memory or any other components on the board so heat sinks are needed for cooling them. But these blocks are cheaper than full cover blocks, can be used on future cards, and are effective. They provide a cost effective solution to a full cover block for a small performance difference.

2. Radiators

This is where it starts to get a little more complicated. There are so many sizes, brands, Fins per inch (FPI), where do you start. What you are going to have to look at first is what you want to cool with your loop and how quiet do you want it.

A CPU only loop is the most simple so we will start with that. Instead of boring you with the facts I'll get right to it. For most modern processors a quality 1x120 radiator with a good fan at a reasonable speed will cool an overclocked CPU adequately. Now some exceptions are CPU's like the 980-990x and 3960x as well as FX-8150 which when overclocked produce much more heat. For those a 2x120 will be needed to keep heat in check. You can go with more radiator size to reduce fan speed if a quiet computer is your goal.

A GPU only loop is the next setup we'll explore. With 2 types of blocks, there will be 2 different levels of heat load to address.

First we will start with the full cover block. This will be close in equavilant to high end processor in heat load, so it should be addressed the same. A generally safe figure is 2x120 per card. So if you are running a 980x and 2xgtx580 full cover block system you would need a combination of radiators giving you 6x120 worth of radiator.

Second is the universal GPU block. This only covers the core of the card, so it is like cooling a second "regular" processor. So with the heat load being similar, the cooling needs will be similar. So you can figure 1x120 per card. So if you are cooling a 2500k and 2x580 universal block system you would need 3x120.

Now these are just estimates assuming that you are using reasonable voltages, and don't mind a little noise. If you want a truly quiet system then you need to add at least 25% to the radiator totals. And remember it's always better to have a little more than you need, rather than too little. For FPI (Fins Per Inch) it basically tells you what speed fans you need to get your radiator cooling properly. High FPI=High speed fans Low FPI=low speed fans. That is not saying either wont work the other way, but it will be where they perform as intended.

3. Pumps

Now for pumps there are a few choices. The MCP-350 or 355 and MCP-655 are the top choices. These allow for the use of aftermarket tops if you choose to do so (IT VOIDS WARRANTY), which allows you to choose size and type of fittings you use as well as a performance gain. They also make res-tops (reservoir tops) that save the money and space of a reservoir, and at the same time allow fitting choice and performance gain. There are other cheaper options, but remember that you get what you pay for. If you are on a tight budget, then EBAY is a good option to pick up a used pump (also no warranty to worry about).

4. Fittings

Barbs or compression fittings? Which one is better? I'm sure that there are several people on this forum that have answered these questions so many times that they recite the answers continually in their nightmares. Which one looks better to you or is more affordable to you are the real questions you need to be asking yourself. Both function well for their intended purpose. The only concern is that on some CPU blocks the holes are not spaced far enough apart to fit regular compression fittings, so swivel compression fittings must be used. A search of reviews for the block you are considering should tell you if there is a clearance issue. Make sure with compression fittings that you match the tubing size that you use to the required size of the fitting. If it says 1/2" ID 3/4" OD don't use any other size than that or it could leak or worse come off the fitting and spray all of your components.

5. Tubing

There are many different kinds and sizes of tubing to choose from. Some being ClearFlex, Tygon, PrimoFlex, and DreamFlex. I personally recommend staying away from the cheapest stuff (usually named clear PVC tubing or ClearFlex) because it clouds quickly. Tygon can cloud eventually, but it takes much longer. Basically anything but the cheapest stuff will work just fine.

6. Additives

Contrary to many people's belief who are new to water cooling, coolant is not needed and is not a good idea. Coolant can clog up water blocks, clouds tubing, and costs unnecessary money. Plain distilled water with either a silver coil (kill coil) or a biocide (PTNuke) will perform the best. If you desire a color for your water, concentrated dyes can be purchased and work well.

7. Don't mix metals

Don't put copper water blocks in a loop with an aluminum radiator as this will cause galvanic corrosion. Nickel plated blocks are fine with copper blocks though, as are stainless steel blocks. JUST SAY NO TO ALUMINUM

8. Leak test the loop

Always leak test the loop without the computer system powered up. Disconnect all power connectors except for the pump, then on the 20/24 pin connector jumper the green wire to any black wire. A paper clip will work fine as long as it dosent touch the case or the board. Place paper towels under the water blocks and around the fittings.observe the system over the course of 1-2 hours at least for leaks. If you find one correct the problem and make sure to give ample time for any components that may have got wet a chance to dry. Once you are certain there are no leaks and very few if any air bubbles, then you can start up the computer. Check your temperatures, and bask in the knowledge that you are now a water cooler.

If you want to learn more on the science of water cooling, look at the following thread.

Good Luck
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nice writeup!

I reccomend (and i think most people on the forum will agree with me here) that you rewrite the part about dies to advise against the use of them becuase they clog up your waterblocks.

other than that everything looks rlly good!
nice writeup!

I reccomend (and i think most people on the forum will agree with me here) that you rewrite the part about dies to advise against the use of them becuase they clog up your waterblocks.

other than that everything looks rlly good!

Generally speaking, concentrated dyes don't clog up water blocks. They might at most color the tubing, and might leave a very slight film on things. Which compared to coolant is a very small problem, and with regular flushes and cleanings it is a moot point. I am glad you appreciated the write-up. I spent quite a bit of time on it, and made it as easy to understand as possible. If this write-up helps at least 1 person considering water cooling it will be worth the effort. I wish there had been something as straight and to the point when I started water cooling.
Looks Great! :thup:
Id still recommend colored tubing over dye. But like you said there are some dyes that wont do much other than tint the tubing.