Richard A. Millard (Office Manager)

The Hidden Pitfalls of Liquid Cooling

Written on March 11, 2013 by

This is going to be an unusual blog post, because I'm going to try and talk you out of one of our most impressive (and expensive) products. This isn't the sort of thing you'd normally see on a commercial website, but I guess we're not your normal commercial blog either. Today I'm going to try and convince you that you don't need a fully liquid cooled system.

I've been with Puget Systems for about 10 years, and I've seen pretty much every kind of system cooling under the sun. When I refer to a “fully liquid cooled system”, I mean a system with a dedicated radiator and pump which cool multiple points within the system (usually CPU and video cards, and sometimes the chipset or other parts too).
When I consider the various reasons that someone is usually interested in a liquid cooled system, they generally boil down to two categories:
Cooling Performance
This includes people looking to keep their system extra cool, people who want to overclock, and people who are packing so much hardware into the computer that you need liquid cooling to reach it all.
It looks really flippin' cool
It's the hot rod of PC building - it looks really cool and all your friends will be jealous. It might not be very practical, but that's not the point. Pompadours aren't very practical, but that never stopped Elvis, did it?
Seriously, look at that thing!

The Hidden Pitfalls

To start, let's cover the drawbacks of a fully liquid cooled system.

The first, and the most important, is just the additional risk of failure in the system. A liquid cooled computer is far more complex than your standard air-cooled system. You still have all the traditional points of failure, such as a video card failing, or a stick of memory going bad, but you now add in a dozen or so additional failure points in hoses, barbs, radiators, waterblocks, pumps, and everything else. Some people think that liquid cooling (and lower temperatures) will improve the stability of a system, but our numbers suggest otherwise. Our most stable systems use the tried-and-true K.I.S.S. (Keep It Simple, Stupid!) philosophy.
Another major drawback is the complexity of the repair work if something goes wrong. In an air-cooled system if your video card should happen to die (and trust me, these things can happen), the fix is simply swapping in a new one and maybe reinstalling drivers. In a liquid cooled system, you have all the hassles of replacing a card that's part of the liquid cooling loop. This often means draining the whole system, or using some hose clamps, and a host of other concerns that most people wouldn't want to deal with. In fact, it's hard to find a local computer shop with a lot of hands-on experience with liquid cooling. In these cases, a little problem can become a major problem in a hurry.
There's other pitfalls too. Liquid cooled systems require maintenance, you may have to periodically top-off the fluid levels. They're extremely heavy, and much more difficult to ship safely. (Tip: If you ever need to ship a liquid cooled system for any reason, it's often a good idea to drain the fluid first and then refill it on the other end of the trip).
It's also worth noting that a liquid cooled system is a fair bit louder than most of our systems. That might seem counter-intuitive, but think about it this way: A well designed system has smart paths for airflow, with several fans and baffles guiding the cool air over hot components. In a liquid cooled system, you take all that heat and funnel it through a single radiator, with only 2 or 3 fans to cool the whole thing, so these radiator fans have to work a lot faster to move off all that heat. Add in the noise of the pump, cavitation noise and the turbulent flow of water through the various parts, and it's simply louder than a system we could build with traditional cooling methods.

Cooling Performance

If you're trying to figure out whether or not you need the cooling performance of a liquid cooled system, I'd start with these two questions:

  1. Are you looking for a system with multiple bulky video cards that will only fit if you replace their stock cooling fan with a liquid cooled water block?
  2. Are you planning on overclocking this system yourself, beyond what the a system builder (like us!) is willing to do?
If you answered no to both of those questions, then you probably don't need liquid cooling.
Everyone assumes that liquid cooling has better performance than air cooling. Why else would it be so expensive, right? It's true that liquid cooled setups are very efficient. However, the important point is that the extra cooling potential is often wasted.
I don't need a car that can go 200mph if I only drive it on roads with a 60mph speed limit, I don't need a 24oz coffee cup if I've only got a double shot of espresso, and I definitely don't need a ton of extra cooling potential if a normal set of cooling fans will keep everything at safe levels.
With a few exceptions, modern hardware has gotten more efficient and less hot in recent years. Even if you're building an ultra-high end rig with the latest processors, a zillion gigs of RAM and multiple video cards, we can cool all that sufficiently without needing liquid cooling. Furthermore, the safeguards on modern hardware overheating have all improved in recent years, so even if it somehow overheated your system is probably just going to turn itself off and not damage anything.
I've pulled data on two different builds of ours from the same time period last summer. They're nearly identical, using extremely high end hardware.
Testing Hardware Liquid Cooled System Air Cooled System
Motherboard: Asus P9X79 Deluxe
CPU: Intel Core i7 3930K overclocked to 4.4ghz
GPU: EVGA GeForce GTX 690 4gb
Chassis Liquid Cooled Antec P193 Antec Nine Hundred Two

The major difference is that one system is built in the Antech P193 Chassis with our Performance Liquid Cooling Package, while the other is built using the Antec Nine Hundred Two Chassis using fan based cooling and a closed-loop CPU cooler. Both are overclocked to the same degree, and here's the temperature results from our benchmarking process:

The liquid cooled system:

The air cooled system:

The red lines are the CPU core temperatures, while the green line is the video card. What we see here is that both systems are showing very stable temperatures. The liquid cooled system's video card stays much cooler, but the processors are running a little hotter. This is because all that heat from the video card is included in the same cooling loop at the processors. The non-liquid cooled system has lower CPU temperatures, and while the video card is hotter it's well within an acceptable threshold.

This data supports my argument that even with modern, high-end, overclocked hardware, liquid cooling is not necessary to sufficiently cool a well-designed system.


No doubt, a fully liquid cooled system can be pretty darn sexy. Ultimately, if that's why you end up buying a liquid cooled system, that's just fine. But you should, at some point, stop and ask yourself whether or not the additional cost, higher failure rate, and everything else, is worth it.

I'll give you a personal example. I really want to buy myself a early-60's Lincoln Continental convertible. Leather interior, check. Suicide doors, check. Massive repair and maintenance costs? Check. Let's be honest though - I live in rainy Seattle, and there's no way I'm going to buy a soft-top convertible when I'd only get to use it twice a year. Still, that doesn't stop me from window-shopping from time to time.
This would be me.

I think that cars actually make a pretty good analogy for computers. They're both costly semi-necessities which cover the spectrum from inexpensive-and-practical to ridiculous-and-expensive.

Here's something to consider though: any time you see a list of average repair and maintenance costs in the car industry, you'll generally find that the 10 least expensive cars to own have names like Honda, Hyundai, Kia and Mazda. The 10 most expensive cards to own have names like Jaguar, Audi, BMW and Mercedes-Benz. Those luxury brand cars are totally awesome, and obviously people love them, but those owners need to be prepared for an extra level of complication and expense if something goes wrong. That same lesson holds true for someone who decides to spend a lot on a great looking liquid cooled system purely for aesthetics and bragging rights.

An Alternative

Okay, I'm done telling you what not to buy. I wanted to wrap this thing up by recommending a compelling alternative instead. I'm talking about “closed loop liquid cooling” (which I'll henceforth shorten to CLLC). This is a self-contained liquid cooling device designed to cool only your CPU. Here's an example:

Unlike a fully-liquid cooled solution, I wholly recommend one of these devices. Let's look at some of the problems a traditional liquid cooling setup has, and compare them to a CLLC unit:

Full Liquid Cooling Closed Loop System
Approx price: +$1000 Approx price: +$50
Very hard to service Simple to service or replace
Lots of points of failure Factory-sealed, never seen one leak.
Adds weight and shipping complications   No heavier than most high end CPU coolers
Requires maintenance No maintenance needed
Comparably noisy A single, quiet (and replaceable!) fan.
To me, that's a pretty strong argument. Unless you're buying a fully liquid cooled setup because you desperately want that hot-rod, these closed-loop systems are the way to go. You'll save yourself a chunk of change on the hardware, a little more on shipping costs, and maybe you'll avoid a major headache down the road.


Tags: Liquid Cooling, Advice

It would be very nice, indeed, if those closed-loop liquid coolers (or "All-In-One" (AIO) as I've also seen them called) could be used to cool a graphics card; one AOI for the CPU, one AIO for the GPU, and an otherwise complete Air-cooling solution would probably rock on toast. Especially since the flaw you cite for the full-system liquid cooling setup, the fact that the GPU's heat is in the same loop as the CPU, would no longer apply.

You'd just need a case that had places to put two radiators, but still have places for normal air-cooling exhaust(s) and intake(s).

Posted on 2013-03-12 10:10:37

Maybe I don't understand, but why not simply put the separate components on individual liquid cooling lines to separate radiators? Do the components not come small enough or something?

Posted on 2013-03-12 12:03:39

Space is a big issue with liquid cooling, and with most modern cases there's just enough room to create one loop that covers everything (gpu, cpu, northbridge etc.). Adding a second pump for a separate loop isn't quite as easy as it seems. You have to leave enough room for your tubing to bend without kinking, and you want to keep things from becoming too tangled. It can be done and I'm sure there are examples out there if you look around, but it's not an ideal solution.

Posted on 2013-03-12 14:07:44

One of the benefits of a closed-loop system, is not having to keep the fluid coolant levels topped up. Also, as I understand it, less risk of potentially-catastrophic leaks.

Posted on 2013-03-18 14:42:05

Have you seen the Ares II? I'm hoping to see more of those pre-installed closed loop coolers on video cards, as video cards are the biggest heat source in most people's systems.

Posted on 2013-03-12 14:09:34

The Ares II seems insane :) 13% performance improvement over a 690 but more than 50% higher cost.

Posted on 2013-03-18 14:09:54

Yeah, the cost is way over the top, IMO. If it were 10% performance for 15% cost, even 20% cost, then I might consider the improved heat-handling to be worth the extra money on a card that's already going to be costing $400 to $1,000.

But if the markup is going to be and stay 50%? Feh. I'd rather wait for the AIO cooling kit manufacturors to come out with something - and then pay Puget to install it for me, hah!

Posted on 2013-03-18 14:45:22
sol666 .

water coolers are still just a gimmick, reality is they are not much better then air cooling under load. plus if the pump dies u are stuck with a heavy hunk of useless GPU PCB and radiator.

Posted on 2016-04-20 15:09:32

Heat is a big concern of mine as I am in the Tropics (temp equivalent of Arizona? Maybe Nevada?) currently with a PC built by Puget Systems (yaaayy!!). I found when I tried the latest Valley benchmark that my graphics card temperature hit about 85 degrees max (7970 Radeon) after just 5 minutes of running and flying through the trees. This got me concerned, and I manually increased the fan speed on the card. It was incredibly loud, but the heat came down dramatically.

That temperature graph for the video card looks fantastic to me. How is the liquid cooling able to produce such a remarkable drop in temperature. It is almost 100% cooler. I would not have expected the difference to be so great.

Posted on 2013-03-18 14:16:08
Pc water cooling system

Thanks for sharing with us.I am really thankful to you for providing the valuable information about Pc water cooling system. I am absolutely valuate your effort.

Posted on 2014-06-13 12:57:41

Good article, exactly the information I needed. Thank you.

Posted on 2014-07-21 06:50:43

Interesting read! I agree with many of your points, but as a DIY watercooler I still use watercooling because it is quieter. A low noise pump and three high quality fans guarantee the system remains inaudible a few feet away, and it specifically does away with the GPU blower noise. It makes no sense to consider that a CPU gets a larger HSF cooler and a GPU a small heatsink and ~80mm fan when the GPU dissipates ~250W and the CPU only ~100W.

I must completely disagree with CLLC systems as you term them. They are proven to fail inside 3 years and not all allow adding more coolant which is always eventually required regardless of what the CLLC claims. The pumps in particular suffer a high mortality rate even within the first year and customers rarely monitor CPU temps or notice until the system begins to crash or restart. This is opposed to a MCP655 pump I've been running 24/7 since 2007, not only does it still work great but the bearing has yet to make any noise. I've seen ceiling fan bearings wear out faster!

Posted on 2014-08-27 15:25:31
Your Numbers Suggest Otherwise

According to your numbers, liquid cooling is very worthwhile. You're only looking at the CPU temps, but the 30-40C temp drop of the video card is why gamers get full liquid setups. Full setups are usually done by people with 2+ video cards, which is what the GTX 690 is. Your CPU temperatures are also mysteriously high. I really don't understand how it got so hot if your setup was done correctly. Every CPU cooling result I have seen is at least 15C cooler, even at peak load.

The last point which is unbelievably terrible is your liquid product comparison. You're comparing a full setup to a single CPU cooler. What? WHAT??? Well of COURSE your pro/con list is accurate! You're comparing 4+ fans to 1 (and there are very quiet models)!!! And if you're going to cry about pumps, they're pretty quiet. If they weren't, gamers wouldn't list "quiet" as a pro. And then $1000 to $50! You can get a proper full setup for $300-$400. What did you buy to reach that number? The most expensive everything? This is so unbelievable stupid and thrown together so half-assed that if it were posted somewhere else I would be tempted to think it was a troll article.

Oh and yes, you do have to check closed loop systems because they DO fail occasionally. If correctly done full systems had a significant failure rate, then people pumping a lot of money into their rigs wouldn't buy them.

Do more research into your topics and use some critical thinking when analyzing your numbers and products. I have a feeling that I'm going to be flabbergasted all day.

Posted on 2014-09-15 16:46:05

Why do I water-cool? Fan-based systems are DUST MAGNETS and I live in a dusty world.
Why do I water-cool? Fan-based systems can get quite loud in quite warm environments, and it gets quite warm.
Water-cooled systems weigh more? Coolant? A pint is a pound, the world around. That's 2 pounds of coolant in a 1 quart system. Cooling blocks? There's another 2 pounds. Radiator? Pump? Another 2-3 pounds. Total? 10 pounds. I don't move my machine enough to care about this.
Points of failure? Plumbing lasts years if not decades, and would last twice as long with controlled liquids suppressing chemical erosion. From my extended family's experience, the most common points of failure are mice, mic-headphone-sets, fans and power supplies in that order (excluding first "things exposed to toddlers or teenagers").
I'll stick to water cooling, thanks.

Posted on 2014-09-23 18:34:57

Liquid-cooled systems still have fans (usually, at least - I have seen maybe two systems ever that were liquid-cooled and fanless) so they still pull in dust. The best solution there - whether liquid-cooling or air - is to use a case with good filtration over the intake fans :)

Posted on 2014-09-23 18:56:54

A lot of liquid cooled systems have more fans than normal air-cooled rigs.

I read this article every time I spend hours just to upgrade two video cards. It could be a simpler task with the use of quick disconnects, but every time that thought occurs to me, I've already spent a fortune on video card upgrades and am in the middle of draining the loop again.

I'm convinced that I enjoy it.

Posted on 2014-10-27 04:06:39

I am using a closed sealed liquid cooler, I find it a better solution than air cooling. In fact I have used all kinds of weird coolers even the highly recommended ones. They are just not on par with liquid cooling especially if you plan to oc. Liquid coolers (not water coolers) unlike popular beliefs are cheaper than some of the after market air coolers, expect to pay between $60 - $80 for liquid coolers. Good air cooling actually climbs in price tag in comparison.

What not to expect:

Liquid cooling is not a refrigerator, might as well live in the North Pole for best results.

Liquid coolers don't leak like water coolers can.

Liquid coolers have a noise reduced fan attached to a radiator.

Liquid coolers use copper face plate for contact and seal the surface between your processor and cooler. Do not tighten it too much otherwise it can brake.

Liquid coolers last longer than air coolers but require a clean environment for breathing. Expect to vacuum out the dust collection otherwise.

Overall these coolers are basically a middle ground between air and water cooling and thus have strengths and weaknesses.

Posted on 2014-12-05 04:59:30

Yeah, closed-loop liquid-cooling has a lot of advantages compared to 'full' liquid-cooling. I think Richard (the author) even mentioned that toward the end of the article. We use closed-loop cooling on many systems, like our Deluge gaming computer (to enable overclocking) and our Genesis workstations (to handle the high heat of many-core Xeon processors).

Posted on 2014-12-05 19:12:56

WOW looks like water cooling got drastically cheaper in 2 years, most coolers i have seen are in the 50-120 dollar range

Posted on 2015-01-26 00:43:52
beth bishop

I know its an old post but it has to said that half of what you said is utter nonsense, for starters most modern pumps are virtually noise free and in regards to the fans having to work that much extra that also incorrect, the idea of a radiator is it spreads the heat within all the blades which then takes less air being blown to cool it down.

Posted on 2015-03-31 15:23:26
John Smith

If you want to tell the time, you could buy a $2 watch or if you want to show off, you get a Ulysses Nardin. Some of these liquid cooled rigs look like nuclear reactors-that's the look I'd probably be going for, something that blows people's socks off. Heck if I could jam some esoteric scientific devices in there I would. My current rig has a closed-loop system and it clocks 4.9 ghz, so of course getting high performance from stock products is not hard...but it's about the pizzazz, it's what makes life more fun and interesting. Very sensible and logical article by the way...but my next build will be sexy.

Posted on 2016-03-16 05:01:57
sol666 .

Pros for air coolers: (1) cheap (2) very simple to manage (3) Very easy to install (4) lack complex moving part allows for easy detection of problems (5) source of failure can only be the fan (6) PC case fans come in standard sizes so CPU fans can easily be replaced even with a non-pwm fan though pwm fan is recommended for speed management. (7) I have been using mine for 8 years with only two fan replacements because I live in a very dusty environment and the fans got clogged. Basically until they make a CPU that runs too hot air coolers are practically immortal!

Cons for air cooler: (1) with smaller CPU fabrication cooling is no longer effective, although if u are not an over-clocker then it is more then enough for any gamer
(2) Take up a lot of room in the PC case (3) loudness depends on the fan design (4) damage to the fins or the cooling pipes will make it useless.

Pros for water cooler: (1) extremely cool at least half the temperature of an air-cooler on idle (2) Very quiet (3) doesn't take up a lot of room plus newer MOBO's are geared towards water cooling solutions (4) Don't need a lot of maintenance compared to air cooler...basically a few less places for dust to clog the gears and bearings.

Cons for water cooler: (1) water coolers are not much better then air cooler under load, against the top ranking air coolers a water cooler may only give a few degrees worth of temperature advantage when over-clocked. (2) There are no possible ways to find out if the water cooler pump is failing before it fails this is on the companies that manufacture them because they sacrifice quality and reliability for cost effective manufacturing. (5) most of the parts in a water cooler cannot be replaced, e.g. radiator, cooling pump so if they are damaged consider ur water cooler scrap metal! (4) Water-cooler in general cost more then air-coolers (4) The possibility of failure for water-coolers is far greater because of the pipes that could leak, the liquid coolant that could damage the circuitry, failure of radiator, and failure of pump.

This is my experience with air and water coolers.....U can decide which is better for ur self.

Posted on 2016-04-20 15:00:17

I would largely agree with you, in regards to closed-loop liquid coolers - except that they are not very quiet, or at least not as quiet as properly done air-cooling. You are adding the noise of a pump (though some can be quieter than others) and you still have one or more fans for cooling the liquid as it passes through the radiator. Because the fins of radiators are much more compact, though, the fans used have to push more air to cool effectively - and thus they have to be louder, at least when the CPU is under heavy load and a lot of heat is being dissipated. Those fans also end up being mounted on the edge of a case, where the radiator is positioned, instead of deep inside the case like a heatsink + fan usually is. That is why the quietest systems we build here are done with air-cooling instead of liquid-cooling.

However, all of that only touches upon closed-loop cooling. This particular article was actually about custom liquid cooling loops, and it is also a few years old now.

Posted on 2016-10-26 16:21:35

There are some fundamental flaws in logic within this article. Regardless, it has merit and several good points are made. I do hope the author decides to update it soon, especially considering the huge increase in consumers now watercooling their systems.

Posted on 2016-09-02 13:47:39

Interesting read, but unfortunately there are so many things incorrect claims here, and some that are just based on ancient watercooling technology that I feel the need to ensure people aren't misled. I just finished building a custom loop for my PC which cools my i5-4670k @ 4.4ghz and GTX 780ti @ 1137mhz without compromising on the quality of parts for only $270. My CPU used to idle around 45'c and under max load would hit well into the 80's. Today under water it's idling at 33'c and hasn't gone above 50'c a single time even using the most rigorous torture tests. But the main reason I water cooled was the GPU temps which would easily climb close to 90'c causing the card to throttle itself and turn the game into a stuttering mess. My GPU is now idling at 28'c and has yet to go over 38'c.

Some additional points...

- Modern pumps like my 10w Laing DDC310 from Alphacool is completely silent. If you put your ear to it you can kind of hear a faint electrical noise.

- Many radiators are designed for low speed fans that run from 600-1000rpm and are so quiet you can hear a mouse fart from across the room. My fans run at 1400rpm on my 360mm radiator to achieve the temps i see and you can barely hear them. A mechanical hard drive noise is far more pronounced. A properly set up water cooled PC is dramatically quieter than any air cooled PC.

- while on the topic of noise I also wanted to point out how loud modern graphics cards are when they are under heavy load. My GTX 780ti sounded like a jet taking off with that fan running at 5k rpm and its not even considered a very loud card. AMD has some real ear bleeders such as the R9 290x which screams at around 48 DBa. There isn't a fan in my PC that goes above 30 DBa. (every 3 DBa is 2x the sound level).

- Air cooled systems also require maintenance. I'm not sure where you get off claiming they don't. It takes me 15 minutes to drain, flush, and refill my loop every 9 months to a year. By telling potential customers that there is zero maintenance with air cooled PCs, you are flat out lying to them in order to make a sale. This is what will happen to their computer a few years down the road with zero cleaning:
http://blog.stevescomputerrepa... (I have no affiliation with this site. just an image i jacked off google)

- Telling potential customers that water cooling costs $1k+ is, once again, a complete fabrication and i don't understand why you'd lie like that. Kits start as low as $180 from respected companies and can run as high as $500. Of course you could build a kit piece by piece, selecting 60mm thick radiators costing $180 each, CPU blocks made of 99.3% pure silver from Aquacomputer with a digital display on it for $300, etc etc... and maybe get over $1k in cost when all is said and done, but for 99.9% of people watercooling their PC, they can cool their CPU and GPU with quality parts for under $400.

Ok. My work here is done. Its a shame I came across this article while helping a friend look for a new graphics workstation because I just can't let him buy a system from someone who lies to his potential customers.

Posted on 2016-11-11 02:47:28

I use CLLCs a lot. Of course my CPU gets the treatment. Then, here's what i do with my GPUs:

No maintenance, and installation is just a bit more technical.

Posted on 2016-12-22 23:34:38
Anun Omus

While I understand this "blog" is 4 years old and a lot of things have changed in terms of liquid cooling performance, very little has changed in air cooling performance. But you cannot base a decision of "To liquid cool or not" on comparing a manufactured closed loop liquid cooling kit that uses 1/4" tubes, no reservoir and a thin 120mm radiator to a custom designed liquid cooling system that uses 1/2" ID tubes, has a huge reservoir and a thick 360mm radiator using push/pull. The more water you have in the system the higher the performance is going to be in term of liquid cooling. Even in 2013 this holds true and is exactly why these closed loop manufactured water cooling kits are no better than air cooling as can be clearly seen by your "numbers". Blind leading the blind is all I learned from this "Blog".......

Posted on 2017-03-27 16:04:49
Brandon Sapp

So I have AMD's 220w beast that requires liquid cooling out of the box and I overclock.. while running a server and client simultaneously on closed loop. Is a custom loop really overkill in my situation? I've been posting 65 degrees Celsius and wouldn't like to burn up my third CPU.

Posted on 2017-04-08 06:52:10

Some form of liquid-cooling is pretty much required for those crazy AMD chips. I personally am not a fan of custom loops, because of the cost, complexity, difficulty to upgrade, and risk of leaking... but if you have the time and expertise to set one up you have more reason to do so than most folks. I'd just go with a closed-loop cooler myself, but you also have to be a little careful with temperature readings on AMD systems since they don't seem to be as reliable (in my experience) as Intel platforms.

Posted on 2017-04-08 20:52:25