3/8 vs 1/2 inch Tubing, is bigger better?

So I just got my Maximum PC April issue where they talk about water cooling. One part of the test they talk about tubing size. Quoting the article, "Tubing is everything, 3/8-inch-diameter tubes spiked our temperatures on 100 percent CPU use to an average of 81 C and a maximum of 83.5 C. The same cooling setup using 1/2-inch tubing hit an average of 73 C with a maximum of 75.25 C. The more fluid you can move over your heat exchanger, the cooler the average temperature that fluid will be that's why 1/2 inch tubing wins."

I didn't think that made such a big difference but 8 C is quite a bit considering that a if a CPU block was 8 C better everyone would use it over another. You will have to read the article to see the test equipment. What do you guys think about it? Should I use 1/2 over 3/8 inch? I already have 3/8 tubing and barbs. :confused:

The differences assuming 10ft of tubing between 3/8" and 1/2" should not account for more than about 0.2C at most if you're over 1GPM.

You would have to be in the .4 to .6GPM range to start seeing differences that large and that is simply hard to do with any of your common good pumps.

Are they using a H50 pump?...:)

There was a test on tubing size done by someone - I don't remember who exactly (skennee probably) and the difference was minimal.

Cathar's test says otherwise, but I guess it depends on more than just the tube size.

For example, when the magazine guys changed tubing on their setup, did they remove the blocks and reapply TIM? TIM done badly can easily account for 5-6 degrees.
Did they do both tests in the same ambient temperature? Could vary by 4-5 degrees if it's a common household, I guess?
Perhaps their 3/8 tubing needed more 90 fittings in order not to kink? Perhaps when they installed 3/8 it WAS kinked, and they just didn't know it mattered much?

Apparently they used a MCP655 for their "custom" build. I didn't think it mattered as much as they say.

The "Other" piece that's missing at least in the estimator and pretty much any pressure drop is the effects of 3/8" barbs. While the tubing may not have much restriction, the barbs and elbows of smaller sizes probably add up to even more restriction. I still don't see how it could be that much completely because of tubing size alone.

I suppose it also depends on the CPU block used, some of the older "Large Channel" blocks were much more sensitive to flow rate than your typical .3mm microfin type block from today's latest design. I have an old "Stinger V8" that was one such block....it LOVES high flow, but it pretty much relied on a nozzle to do the work and had little to no pin/fin heat transfer.

Anyhow, I suspect it's ambient or other testing error. Unless you are running 100' of tubing or small 3/8" barbs, 3/8" tubing will not be worth 7C over 1/2"....just not possible for your typical system.

First and foremost, let's begin with the source.:rolleyes:

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Originally Posted by Feklar

Apparently they used a MCP655 for their "custom" build. I didn't think it mattered as much as they say.

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I have seen people "Mistake" the arrow direction on the vario. If they were accidentally running at setting 1 instead of 5...I could see a big difference there. Setting 1 and 2 are REALLY low in pump power. You would be probably in the .5GPM range.

I agree, something is amiss with their test to account for such a large difference. If you don't have a lot of water cooling experience and read the article it makes you second guess your choice in equipment unless you get other opinions.

All I can say is "That poor, poor cat".

Yea I called my wife from work on Valentine's Day and told her to get the kitty ready. When I came home she did that to the cat.

Hmmmmm, this is a tough one. What would be the optimal tube size to use in your "cooling" loop? Either the smaller more restrictive size, or a larger less restrictive size? :eh:

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Originally Posted by SlowSVT

Hmmmmm, this is a tough one. What would be the optimal tube size to use in your "cooling" loop? Either the smaller more restrictive size, or a larger less restrictive size? :eh:

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Did you read the replies offered thus far? :rofl:

The last place I would get water cooling advice is maximum pc

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I get Maximum PC and like the magazine, but they really should do a bit more homework before they publish stuff like this claiming a 10c difference.

I personally think that we should all just go ahead and use 1" tubing. That should net us at least a 20c reduction in temps, right?

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Originally Posted by voigts

I personally think that we should all just go ahead and use 1" tubing. That should net us at least a 20c reduction in temps, right?

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You're still using tubes measured in inches? Pft, what a noob, 1/2 foot diameter is where it's at!

;)

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Originally Posted by theseeker

First and foremost, let's begin with the source.:rolleyes:

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Originally Posted by Aaronharmon

The last place I would get water cooling advice is maximum pc

Sent from my Droid using Tapatalk

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^This...+1^

meh tubing size is all moot once u get to 3/8ths.

I mean from 1/8 to 1/4 you will see a difference, but once u get to 3/8ths it all changes.

The reason for 3/8ths in reality was the thicker wall they brought.
This helped us a lot for bends b4 we had 90's and other adaptors.

Also it helped a lot in getting South Bridge, and SLI cards b4 we had options for that.


The biggest lesson to learn is, if your going 3/8ths, you need to stay with 3/8ths otherwise cost will rise because of the requirement of different tubing.
and with the availability of options on our end now in fittings, you really dont require that thicker wall for bends. You just use an adapter.

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Originally Posted by antiacid

You're still using tubes measured in inches? Pft, what a noob, 1/2 foot diameter is where it's at!

;)

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Rofl hahahaha xD

Sent from my PC36100 using Tapatalk

using tubing at all is so prehistoric. Now all the hype is direct teleport of water between waterblocks and rad. Zero flow resistance on tubing part and you don't need pump!

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Originally Posted by vhaarr

Cathar's test says otherwise

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Exactly the thread I would have linked to.

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Originally Posted by theseeker

First and foremost, let's begin with the source.:rolleyes:

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Originally Posted by Aaronharmon

The last place I would get water cooling advice is maximum pc

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^-QFT. I spent hours on the phone with those bozos a few years ago (2007?) when they were wanting to write a water cooling feature and water cool their annual 'ultimate gaming PC' build. Totally clueless. My opinion of them also wasn't helped when I sent them a complete custom cooling kit (done specifically to meet their needs) for the water cooling feature they were planning on doing... which they never ended up doing (they just briefly mentioned the kit in an article where they were playing around with a FLIR camera instead). Then they asked me for another complete system like a month or two later for the gaming PC build.

Umm, I don't mean to be cynical but the purpose of a magazine is to make money selling advertisements, not to tell you the truth. The articles that appear in magazines are bad for several reasons: (1) they tell you what you want to hear, because that makes you want to buy the magazine; (2) "product reviews" invariably recommend products made by the biggest advertisers in the magazine; and (3) the publishing industry generally has contempt for the articles themselves, as the industry refers to the articles as the "news hole" in the magazine, because that is the part of the magazine they can't sell to some advertiser. Hence, my point is that Maximum PC is no better or worse than any other magazine, as it is written by the same kind of "magazine journalists" who write articles telling you that can lose 10 pounds in three days by eating only cheeseburgers, or that you can get a six pack of abs by exercising in your chair for 5 minutes a day. So it's not surprising to me to read in the pages of Maximum PC that 1/2" tubing can yield a 10C drop in temps. (Load/ idle, who cares? It's all good.) Now I'm waiting for next month's issue, to find out that switching to 1/2" tubing will help me trim my gut as well, because that is news I can use. :up:

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Originally Posted by eth0s

Umm, I don't mean to be cynical but the purpose of a magazine is to make money selling advertisements, not to tell you the truth. The articles that appear in magazines are bad for several reasons: (1) they tell you what you want to hear, because that makes you want to buy the magazine; (2) "product reviews" invariably recommend products made by the biggest advertisers in the magazine; and (3) the publishing industry generally has contempt for the articles themselves, as the industry refers to the articles as the "news hole" in the magazine, because that is the part of the magazine they can't sell to some advertiser. Hence, my point is that Maximum PC is no better or worse than any other magazine, as it is written by the same kind of "magazine journalists" who write articles telling you that can lose 10 pounds in three days by eating only cheeseburgers, or that you can get a six pack of abs by exercising in your chair for 5 minutes a day. So it's not surprising to me to read in the pages of Maximum PC that 1/2" tubing can yield a 10C drop in temps. (Load/ idle, who cares? It's all good.) Now I'm waiting for next month's issue, to find out that switching to 1/2" tubing will help me trim my gut as well, because that is news I can use. :up:

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Although your reasoning makes sense generally, it doesn't really apply here as the difference in tubing size doesn't benefit any manufacturer or advertiser in their magazine. This is purely ignorance and a lack of proper testing methods.

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Originally Posted by Sideroxylon

Although your reasoning makes sense generally, it doesn't really apply here as the difference in tubing size doesn't benefit any manufacturer or advertiser in their magazine. This is purely ignorance and a lack of proper testing methods.

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Sense of humor much?

Somehow I lost you in making my point by trying to be funny, which is my fault I guess. What I was trying to say is that the magazine is not interested in curing their own ignorance or gaining knowledge, and they certainly don't care about "proper testing methods". All they want to do is sell magazines, because they make money from the ads that appear in the magazine, which they then use to pay themselves huge bonuses, and then they go play golf, have a few drinks and laugh at the nerds who argue about the veracity of the testing methodology used in their magazines.

Let me put it this way: magazine buying people want to read articles that say that 1/2" tubing is better than 3/8" tubing, so that is what gets written in the magazine. The publisher of Maximum PC is giving his readers what they want. Maximum PC doesn't care about "proper testing methods", because they already have their conclusion, and the testing doesn't really matter. Furthermore regardless of the testing methods used or not used, after the story has been written, an editor at the magazine will change the "findings" to give the story the most "sizzle". In this example, I'm sure the editor decided that a 10C delta was a more exciting finding than a .5C delta (which was closer to the actual truth), and so the editor changed the copy. In conclusion then, your allegation of ignorance on the part of the magazine people is completely inapt, for it presupposes a level of conscience that is wholly absent in commercial publishing. In other words, they don't really care about the science or the facts. All they care about is selling magazines, so they write stories that they think people want to read, even if they have to "fudge" the findings.

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Originally Posted by eth0s

Let me put it this way: magazine buying people want to read articles that say that 1/2" tubing is better than 3/8" tubing, so that is what gets written in the magazine.

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Are you still trying to be funny? Why do you think people want to read that? I think the average person reading that mag could care less.

I've read that mag for years and have always found their reviews straight forward and fair. Maybe I'm being a bit naive here but I believe for the most part they try to present the facts and not "what the reader wants to read" or what the manufacturer wants them to print. If that was the case they wouldn't have lasted all these years just printing bull:banana::banana::banana::banana: like that.

I still think it just came down to them getting it wrong this time and not posting those results because the editor thinks that's what we want to read.

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Originally Posted by Sideroxylon

I still think it just came down to them getting it wrong this time and not posting those results because the editor thinks that's what we want to read.

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Indeed, eth0s could be right about magazines in general (but I don't think he is, since in the end you just shoot yourself in the foot by not being honest), but in this case noone gains from this sort of statement.

They're probably new to testing extensive cooling equipment and have to get their feet wet! I wonder how many times that joke has been pulled in here?! :rofl:

They're only stuck 7 - 8 years in the past. they should add water wetter.

The author of the Maximum PC article has posted some responses. It's worth looking at...Build It: Three Water-Cooling Techniques Detailed and Constructedd

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Originally Posted by penguins

They're only stuck 7 - 8 years in the past. they should add water wetter.

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lol that stuff brings back memories

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Originally Posted by Sideroxylon

The author of the Maximum PC article has posted some responses. It's worth looking at...Build It: Three Water-Cooling Techniques Detailed and Constructedd

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what a funny review, nothing about it makes sense...

• why spend 150$ on quick disconnects?
• MCP655 is 105? where at, id love to pay 30$ over other sites.
• how did they find a 7c difference between top blocks? our experts see like 1-2c difference.
• a 10c increase on 2/3" tubing means they messed up somewhere else
• dont double on on rads, lol, sure lets quadfire on a single H70, cause one is more than enough, nomatter how thick or wide.
• special coolants sure might not improve temps, but they serve other purposes too that obviously mean nothing.
• wheres the fan noise comparison? cause thats a MAJOR reason people go for WC

In his comments he's actually stating almost a 15c swing in temps when using 1/2" over 3/8" tubing. :shakes:

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Originally Posted by Sideroxylon

The author of the Maximum PC article has posted some responses. It's worth looking at...Build It: Three Water-Cooling Techniques Detailed and Constructedd

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I cant stand Maximum PC... A bunch of amateurs.

Yeah Maximum PC is like FM forums these days. They would prolly use this crappy article as a proof to their ridiculous claims that bigger tubing is indeed a lot better. Like a LOT better.

edit : oh yeah i even used a 5/16" i think tubing that came with a Zalman Res-X unit and the difference in temps in my loop (i7/GTX480/chipset/480mm rad area) was minimal at best.

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Originally Posted by Sideroxylon

In his comments he's actually stating almost a 15c swing in temps when using 1/2" over 3/8" tubing. :shakes:

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I hate to say it, but I just got my GTX580 to drop 25C by going back to 7/16 from 3/8 tubing.

I'm not saying they are good reviewers ... but even a broken clock is right twice a day.

J

^ theres no way the tube size made that much difference. Somthing else was the problem.

I swear the only things that changed were the tubing size and the fittings to go with it.

J

what were the before/after temps and whats all in the loop?

i wonder if you went from .1gpm to like .3gpm, both low numbers but you might have been too restrictive to start

More details here (I don't want to thread hijack)...

http://www.xtremesystems.org/forums/...d.php?t=267645

Going to a larger tube size is not likely to lower temps unless the tubing was too small to begin with and impedes the volume of water circulating within the loop. The larger tube size should decrease the resistance the pump must overcome. I used 1/2" ID tube throughout my system. I don't think you can go wrong here by going BIG!

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Originally Posted by Sideroxylon

The author of the Maximum PC article has posted some responses. It's worth looking at...Build It: Three Water-Cooling Techniques Detailed and Constructedd

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I see only 1 thing they got right.

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5. F%@& Fluid

If you buy expensive fluid expecting it to be the elixir of the gods for your water-cooling setup, you’ll be disappointed. In our tests, $2 distilled water worked just as well as the most expensive water-cooling fluid we could find—$50 a bottle.

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otherwise...I need to a larger version of Biker's avatar

http://img808.imageshack.us/img808/1...piditburns.jpg

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Originally Posted by brammers

More details here (I don't want to thread hijack)...

http://www.xtremesystems.org/forums/...d.php?t=267645

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i briefly read over it, interesting experience there. and i dont think your hijacking this thread, since its all about how 3/8" is negligible, but yet you have a valid case where it was an issue.

your simple issue probably provides us more information than that 3 page review :D

i would think that when you have that many components you would want a flow meter of some kind (are there cheap options that give you a useful quantity of speed? and not that little thing that just spins and you cant tell how fast)

and did someone do a test about spread out pumps so the order would be
something > something > pump > something > something > pump >
vs
something > something > something > something > pump > pump >
and how much flow is changed?

*sigh* ... I don't think there is any way to win this one ...

I wana see them go liquid nitrogen, that way I can try out my new popcorn maker.

Sent from my X10a using Tapatalk

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Originally Posted by Sideroxylon

The author of the Maximum PC article has posted some responses. It's worth looking at...Build It: Three Water-Cooling Techniques Detailed and Constructedd

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@ Sideroxylon: Well, at least we can agree that Maximum PC suxx. :up:

@ everybody: As for the actual debate of 3/8" v. 1/2" tubing, IMHO bigger tubing is always going to be better for cooling performance. But some people need to use 3/8" for tighter bends. Or b/c they like the way it looks, which are both valid reasons to use it.

@ brammers: maybe you got such great results, b/c you switched to 1/2" fittings. Those 3/8" fittings themselves could easily have been the most restrictive points in your loop, other than your CPU block. Getting rid of those 3/8" fittings maybe gave you a huge increase in flow rate. But I don't know, maybe it was something else, like re-seating the block(s), getting rid of accumulated dust, a change in air flow, or maybe it was a combination of things, in addition to the bigger tubing and fittings. (lower ambients always help too!)

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Originally Posted by eth0s

@ brammers: maybe you got such great results, b/c you switched to 1/2" fittings. Those 3/8" fittings themselves could easily have been the most restrictive points in your loop, other than your CPU block. Getting rid of those 3/8" fittings maybe gave you a huge increase in flow rate. But I don't know, maybe it was something else, like re-seating the block(s), getting rid of accumulated dust, a change in air flow, or maybe it was a combination of things, in addition to the bigger tubing and fittings. (lower ambients always help too!)

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Agreed on the fittings. All else remained the same. I suspect you'd see a lot less difference if you put 3/8 tube over 1/2 barbs and compared it to 1/2 (or 7/16) over 1/2 barbs.

For the record, I'm not doubting Vapor's superb comparison on tubing sizes. Just saying what I found.

J

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Originally Posted by eth0s

@ Sideroxylon: Well, at least we can agree that Maximum PC suxx. :up:)

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Sorry, but I don't agree with you on that. I was actually bummed when I read this article. I enjoy the mag and have based many of my past purchases on their reviews.

In this case they just flat out got many things wrong. They need to stick with hardware reviews and stay away from cooling. It's apparent that their knowledge and testing abilities/methodologies are sorely lacking.

welllll, after thinking about it, I posted a comment on the article. Martin210 came along later and posted a great comment.

I'm not at all suggesting we join forces to post comments (in fact, I think that is expressly against XS forum rules) ... but, if anyone does add a comment, please take a constructive approach.

I don't hate Maximum PC because of this article (it's not the first one on Water Cooling that hasn't been quite right). They do have good info on other stuff. I truly believe it's a matter of inexperience in cooling, and not malicious intent to misinform.

Cathar tested this about 4 years ago...


http://www.xtremesystems.org/forums/...d.php?t=147767

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Originally Posted by tw33ter

Cathar tested this about 4 years ago...


http://www.xtremesystems.org/forums/...d.php?t=147767

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My bad, thought it was Vapor.