The impact of tubing sizes

C

Cathar

[H]ard|Gawd
Joined
Apr 15, 2001
Messages
1,057
I've been working on a wholistic guide to designing a water-cooling system of late. Using a mix of real-world test data, and calculating pressure drops, I've been able to put together an analysis of the impact of tubing sizes on CPU temperatures.

The radiator and waterblocks are:

Thermochill PA120.2 with 2 x Yate-Loon fans at 12v
Swiftech Apogee GTX
Conroe C2D CPU, overclocked and under load, emitting 100W of heat
2 meters of tubing length

Loop order is pump->radiator->waterblock->pump

Using 1/2" ID tubing and 1/2" OD barbs, I determined the pressure-drop curve for the system. Using Swiftech's published test data for the Apogee GTX, and a flow-performance curve for the PA120.2, we're able to determine the pumping hydraulic power required to push various flow-rates. Using established typical ratios of hydraulic power to actual power draw and heat dump of known real-world pumps, we're able to throw into the mix the amount of pump heat dump required to push any flow rate. We first establish this independently of an actual pump (i.e. determine the theoretical best pump), and then select an actual real-world pump that best suits the theoretical target, and then using the PQ curve of that pump, determine the final flow rate of the system, and hence the correspondent final CPU temperature.

Now in a wholistic model, we're modelling not just the impact of the water-flow rate on the CPU temperature, but the impact of the total heat dump of the cooling system (CPU, pump, radiator fans) has on the room environment, which in turn raises the temperature of the air in the room, and so in turn raises the water temperature because the air-in temperature into the radiator will have warmed up. The effect is very small, but I still model it.

Global temp = 22C
Room C/W = 0.005
Fan Heat Dump = 2.0W

The proposed tubing sizes and fittings we'll be investigating are:

6.35 (1/4") ID tubing with quick-fit fittings
8mm (5/16") ID tubing over 6mmID|8mmOD barbs
8mm (5/16") ID tubing with quick-fit fittings
9.6mm (3/8") ID tubing over 7.5mmID|3/8"OD barbs
9.6mm (3/8") ID tubing with quick-fit fittings
11.1mm (7/16") ID tubing stretched over 10.5mmID|1/2"OD barbs
12.7mm (1/2") ID tubing over 10.5mmID|1/2"OD barbs

Quick-fit fittings are those similar to those found on the Swiftech MCW50 (http://www.swiftech.com/products/mcw50.asp)

Running the above range of tubing/fitting sizes through the optimal pump power estimator software I wrote, it predicts that the best pump to use is one that's consuming around 10-13W, with optimal pumping efficiency in the ranges of 3-6LPM. I won't go into the intricacies of the pump power estimator. It's not an exact science, suffice to say that it looks at the wholistic scenario given a waterblock, heatload, room C/W, radiator, system restriction, and so on, and puts out a suggestion for where the optimal range of pumping power lies for that setup. This allows us to then pick a real pump that closely matches the suggested pumping characteristics.

Using the Laing data here: http://www.laing.de/file/66 we see that an unmodified DDC1+ (more commonly referred to in forums as the DDC2) is a very good pump fit for our scenario. Another excellent alternative would be the DDC1 with a modded top.

Okay, so our optimised system consists of:
Laing DDC1+ (unmodified)
Thermochill PA120.2 with 2 x Yate-Loon fans at 12v
Conroe C2D CPU, overclocked and under load, emitting 100W of heat
2 meters of tubing length

For the various tubing/fitting sizes, the PQ curves for a full system for each tubing type looks like this:

tubings.png


I overlaid the curves onto the PQ graph for the Laing DDC1+

The flow performance curves for the radiator and waterblock are illustrated on the following graphs:

tubing-block-cw.png

...and...
tubing-rad-cw.png


The total CPU heat load is 100W. The total system heat load is 114W . We assume a fixed 14W heat dump from pump which was derived from other testing. This does in fact vary a little as we can see by the Laing graph. As flow rates decrease, so does power draw, and therefore the heat-dump as well. For simplicity we'll assume a fixed 14W heat dump for now.

The intersections all are:

6.35mm quick fit = 4.45LPM flow, 0.0795 block c/w, 0.0374 rad c/w
8mm barbed = 4.75LPM, 0.0783 block c/w, 0.0373 rad c/w
8mm quick fit = 5.6LPM, 0.0770 block c/w, 0.0369 rad c/w
9.6mm barbed = 5.7LPM, 0.0768 block c/w, 0.0369 rad c/w
9.6mm quick fit = 6.2LPM, 0.0762 block c/w, 0.0367 rad c/w
11.1mm barbed = 6.3LPM, 0.0761 block c/w, 0.0367 rad c/w
12.7mm barbed = 6.35LPM, 0.0760 block c/w, 0.0366 rad c/w

Final CPU temperature is ambient (22C) + system load (114W) * radiator C/W + CPU Load (100W) * block C/W

The final CPU temperatures work out to be:

6.35mm quick fit = 34.21C
8mm barbed = 34.08C
8mm quick fit = 33.91C
9.6mm barbed = 33.89C
9.6mm quick fit = 33.80C
11.1mm barbed = 33.79C
12.7mm barbed = 33.77C

So there we have it. The differences between varying tubing sizes.

Okay, the more astute of you will point out that the block C/W is really the case-to-block C/W, and that the actual CPU-die-to-block C/W is a lot higher. Even if we triple block the C/W (which would be an absolute upper limit based upon older research), we get:

6.35mm quick fit = 50.11C
8mm barbed = 49.74C
8mm quick fit = 49.31
9.6mm barbed = 49.25C
9.6mm quick fit = 49.04C
11.1mm barbed = 49.01C
12.7mm barbed = 49.00C

I'll leave it to everyone's own personal value based judgement to determine the relative importance of the differences seen....

It's certainly not the 5C figure that people bandy about. I never expected that it ever would be myself. In my own testing with arbitrarily choking the flow-rate in a test-system, I've always been amazed at the low flow resilience of many setups. Below 2LPM is where things start getting pear shaped quickly for most systems. My recommendation is that even if you're a low-flow fanatic, always ensure that your flow-rates are above 2LPM at the very least, and preferably above 3LPM if at all possible. Still, even when given 1/4" tubing installed with quick-fits and a decent pump like a DDC2, we can see that flow-rates in excess of 4LPM aren't a problem.
 
bit-clap.gif
bit-clap.gif
bit-clap.gif



My experience with the Aquastream has been that if you OC the pump into the 70's range you should be well into the 3 LPM range providing you don't run more that 4-5 blocks. From what I have heard from others the Innovatek HPPS pump (another Eheim 1046 deviant) runs very similar.
 
interesting findings, looks like 3/8" ID could be the new standard in big bore setups.
push fittings would be the ideal setup but I wonder if 3/8" ID tubing forced over 1/2" barbs (10.5mmID) would net the same results?
 
_G_ said:
interesting findings, looks like 3/8" ID could be the new standard in big bore setups.
Click to expand...

Just my opinion:

Small bore = <8mm or 5/16" ID
Medium bore = 8mm-10mm ID
Big Bore = >10mm ID
 
_G_ said:
interesting findings, looks like 3/8" ID could be the new standard in big bore setups.
push fittings would be the ideal setup but I wonder if 3/8" ID tubing forced over 1/2" barbs (10.5mmID) would net the same results?
Click to expand...
3/8"ID over 1/2" barbs is a royal PITA. Most 3/8"id tubing has the same OD (5/8") as 7/16"id, but it has thicker walls, so it's harder to stretch it out. 7/16"id has thinner walls, and doesn't have to physically stretch as much.

What would be really great if you could dig up some more numbers for different blocks/radiators/pumps to give an idea of different loops. Either Systemcooling had an unusual case/bad mounting/whatever when they saw a 2*C improvement just from switching from 1/4" to 3/8" fittings and tubing. With your data from here, their 1/4" AC loop must have had incredibly low (>1lpm?) flow, or something else was going on.

Not to take advantage of your accident, but if you want something else to do, there's plenty who will appreciate your findings. Maybe even send it off to Overclockers/ProCooling? :D
 
Cathar you are the man!

Funny thing is I have been posting a 2-3c difference ever since I got your Storm block and ran it on 8mm tubing versus 1/2" tubing and that was a few years ago. I guess the only way I was wrong is not enough credit was given to 6/8mm. ;) As a reference I am running a Fuzion -> DDC1 w/ alpha cool top -> PA120.2 with great sucess.
Again, thank you for the time and great information.
 
ikellensbro said:
Either Systemcooling had an unusual case/bad mounting/whatever when they saw a 2*C improvement just from switching from 1/4" to 3/8" fittings and tubing. With your data from here, their 1/4" AC loop must have had incredibly low (>1lpm?) flow, or something else was going on.
Click to expand...

If they were using 1/4" barbs, as opposed to push-fits, that would explain it. 1/4" barbs are insanely restrictive. Also, if the pump is too weak (<5W), or primarily of a high-flow/low-pressure design, this also amplifies the benefits of moving to a larger tubing, and is precisely why, 5 years back, 1/2" ID tubing was justifiable with the weak, hi-flow/lo-pressure pumps that were common-place back then.

By first choosing a decent pump that is matched to the heatload, we can minimise the impact of tubing size changes. Start off with the wrong pump and you can very well see much larger differences.

Get the pump right first (hi-pressure/moderate-flow), which is strong enough to shrug off a little extra tubing restriction, and the differences are much smaller.

Things have changed in the last 5 years, and that's why I thought it important to revisit this now. Given pumps of 5 years ago, such a study would like find that 1/2" tubing is totally justified (and it was back then).
 
R1ckCa1n said:
As a reference I am running a Fuzion -> DDC1 w/ alpha cool top -> PA120.2 with great success.
Click to expand...

You might want to try the Aquastream again if you have it. Make sure you don't have an AC flow meter installed. ;)
 
Good, finally some data on what some of us have understood for quite awhile.

And from Cathar too, always a nice boost to the credibility :).

If only I didn't dislike the look of tubing smaller than 5/8 OD :(
 
Arcygenical said:
If only I didn't dislike the look of tubing smaller than 5/8 OD :(
Click to expand...

:)

Go with whatever floats your boat. I'll do my best to inform people of the realities of the impact of their choice though. I just hope to inform people that the impact of their choice of tubing size is less important than is generally understood.

Mind you, things have changed.

Way back in the day, when many w/c setups were 3/8", and only some were 1/2", we had the super-hot AMD T'bird CPU's, and poorly designed open-flow waterblocks with little internal furniture that demanded that as much flow be rammed through them as possible to perform. Further, most pumps that were available were like the Eheim 1250. High-flow, low-pressure pumps that dumped a fair amount of heat, and radiators taken from cars that also demanded flow rates in excess of 10lpm to get past their performance knee.

i.e. 1/2" ID made sense then. The benefit still wasn't huge over 3/8", but it was noticeable. Tests back then showed that the move from 3/8" to 1/2" meant anything from a 0.2-1.0C improvement, depending on various factors. A 1.0C improvement was enough for most people to make the jump, and so 1/2" tubing got its following.

Fast-forwards to today, and we have well designed middling restriction blocks which are more flow agnostic. We have well designed radiators that are more flow-agnostic (both in terms of fan power and liquid flow-rate). We have pumps that are near optimal for PC water-cooling that strike a good balance between pressure, peak-flow, noise, and heat. In short, everything has, quite rightfully, been pegged back from old-school high-flow excess, and tempered with a more balanced approach. Modern blocks, pumps, and radiators can "shrug off" the impact of smaller ID tubing with little actual noticeable temperature difference.
 
Arcygenical said:
If only I didn't dislike the look of tubing smaller than 5/8 OD :(
Click to expand...

At least we now know it is more about looks than anything else ;)

Cathar said:
Go with whatever floats your boat. I'll do my best to inform people of the realities of the impact of their choice though. I just hope to inform people that the impact of their choice of tubing size is less important than is generally understood.
Click to expand...

Thank you! Maybe this will be taken into consideration more and more instead of feeding the same old configuration to anyone versus understanding what is most important to the end user and tayloring the watercooling solution around the requirements.
 
Now how does this apply to people who are running 6 block long loops, with 1/4" tubing and an Eheim 1048 equivalent pump?

Running a single waterblock loop with a pump like the DDC2, well no shit the tubing makes little difference, there isn't enough of anything in the loop to make much of a difference.

I think what this shows is that the tubing has less of an impact than the pump, and the length of the loop.
 
well maybe not even 6 blocks but how about 3 1 CPU and 2 GPU blocks..


good info

thanks man
 
Cathar - your continued work towards properly researched claims is yet again MUCH appreciated. You're a true asset to the [H] community!
 
Erasmus354 said:
Now how does this apply to people who are running 6 block long loops, with 1/4" tubing and an Eheim 1048 equivalent pump?
Click to expand...

The Aquastream running at 74mhz appears to have about a 3LPH rate so it fits his model.

What he is showing is with todays blocks and pumps, tubing size is less of a problem than people think. You can't run six blocks on 1/2" anyways so running a stronger pump, or multiple pumps, with smaller tubing is the way to over come the size restrictions. This has been suggested but never accepted until now.

Erasmus354 said:
Running a single waterblock loop with a pump like the DDC2, well no shit the tubing makes little difference, there isn't enough of anything in the loop to make much of a difference.

I think what this shows is that the tubing has less of an impact than the pump, and the length of the loop.
Click to expand...

So why has this entire forum been flaming anything less than 7/16" configurations as such an inferior solution?
 
Erasmus354 said:
Now how does this apply to people who are running 6 block long loops, with 1/4" tubing and an Eheim 1048 equivalent pump?

Running a single waterblock loop with a pump like the DDC2, well no shit the tubing makes little difference, there isn't enough of anything in the loop to make much of a difference.

I think what this shows is that the tubing has less of an impact than the pump, and the length of the loop.
Click to expand...

Hmm, the 1/4" tubing+quick-fits accounts for 75% of the total loop restriction in the OP scenario, while the 1/2" tubing+barbs accounts for just 15%. The beauty of it is as flow rate decreases, restriction drops away according to the flow-rate squared, and we're moving upwards on the pressure curve of the pump. This is the real reason why the tubing size makes minimal difference to the flow rates. It has less to do with the pump itself, but rather more to do with how restriction changes with flow.

Still, the DDC2 IS important, because it is operating at near to its optimal efficiency point in the selected scenario. This is actually really important. Get the pump right, and yes, we can mess with the restriction a fair bit and get away with it. Use something like an Eheim 1250 instead and the differences would be larger.

The radiator choice is really important too. We want a radiator with a fairly flat flow-performance curve, especially in the 3-6LPM range. As flow rates drop, we look to the radiator to keep the whole system cool. If the radiator is sensitive to flow rate changes, then we're in trouble.

As for a small pump with lots of blocks. I'll run a quick estimation.

Let's assume a 1048. ~0.9W hydraulic power. ~5.3W actual power. Yes, I know that on the sticker that a 1048 says 10W, but in reality the Eheim pumps do draw around half their stickered power, which was measured (by me) by putting the pumps in an insulated container of known thermal mass and measuring the rate of temperature rise of the water.

Let's primarily concern ourselves with the CPU + GPU temps, We'll assume 80W CPU power, and 100W GPU power. We'll assume that the total heat-dump from the other blocks (chipsets + disks I presume) to be 50W. We'll apply a high level of flow restriction for the sum of the restriction of the 6 blocks in total. A decent educated guess would be around 2mH2O @ 1gpm. That's pretty darn restrictive (equal to about 3 Apogee blocks in series). I may be overstating the restriction here???

The difference between 1/2" barbed, and 1/4" quick-fit, on such a setup I estimate to be:

1/2": CPU = 53.5C, GPU = 47.0C @ 2.73LPM
1/4" QF: CPU = 54.2C, GPU = 47.7C @ 2.40LPM

As you can see, with the amount of restriction of the blocks, the tubing itself has minimal impact on flow rates. Certainly MUCH less than in the OP scenario.

Switch out the 1048 for a DDC2, and we get:

1/2": CPU = 52.4C, GPU = 45.8C @ 4.05LPM
1/4" QF: CPU = 52.9C, GPU = 46.2C @ 3.56LPM

So there you go. The differences are still small(ish) either way. Yeah, there's a ~1.8C difference between a small-bore/weak-pump, compared to a big-bore/strong-pump in such a multi-block setup, but that's only because we've also changed the pump from something that's woefully mismatched to the setup to something much better matched. Keep the pump constant, and the difference between the tubing sizes is actually less than in our OP, which is exactly what we would expect if we think about it.
 
ikellensbro said:
Either Systemcooling had an unusual case/bad mounting/whatever when they saw a 2*C improvement just from switching from 1/4" to 3/8" fittings and tubing. With your data from here, their 1/4" AC loop must have had incredibly low (>1lpm?) flow, or something else was going on.
Click to expand...

The test was somewhat flawed because they used the Aquastream pump at it's stock clock setting. If they would have flipped the jumpers on the controller card to 70 Hz they would have seen an increase in the pump to 8 watts, 2 meters of head, and a major increase in flow.

In my loop I saw about a 1.5 C drop in temps going from the stock clock of 47 Hz to 72 Hz and flow doubled. My loop consists of a Cuplex XT, two Twinplex's, and a block for the voltage regulators for a total of four (4) blocks.
 
Part No. 51025K187 over at www.mcmaster.com appears to be pretty much what I had in mind for a 1/2" OD push-lock fitting. Will fit to 1/4", 3/8" or 1/2" NPT pipe thread size. Technical drawing appears to show that the port ID to be 3/8" ID (i.e. no flow resistance), and appear to show that you could happily apply these with an O-ring seal on the thread section for easy sealed fitment.

Part No. 51235K117 is also another example. It says rated for air only, but it's butyl/delrin, so for use with water should be fine.

Part No. 5111K87 also looks to be the goods.

There are variations on these parts at the site for G/NPT threads, and imperial/metric tubing sizes.
 
Top Nurse said:
The test was somewhat flawed because they used the Aquastream pump at it's stock clock setting. If they would have flipped the jumpers on the controller card to 70 Hz they would have seen an increase in the pump to 8 watts, 2 meters of head, and a major increase in flow.

In my loop I saw about a 1.5 C drop in temps going from the stock clock of 47 Hz to 72 Hz and flow doubled. My loop consists of a Cuplex XT, two Twinplex's, and a block for the voltage regulators for a total of four (4) blocks.
Click to expand...

Is there any rough guestimation maths we can use to work out flow rates? I suspect mine right now are quite low - Aquastream at stock, 6 blocks, lots of 90 degree bends. Moving to 6 blocks, less 90 degree bends, and will be putting the AquaStream up to 70hz, so I'm hoping that keeps the flow rates away from the performance drop off area under 2.
 
How about 45 degree fittings? Before you do that OC to 70 and see what you get. It might not be worth anymore trouble than that. :)
 
45 degree fittings are in the post :)

Surprised they didn't arrive yesterday along with the rest of the stuff.

Aquacomputer are still "processing" my order placed on monday night. :/

When the AquaComputer order arrives I can swap out the AquaStream contoller for the newer one that allows the pump to be set higher, I'll see what effect that has.

I'll still be using lots of 90 degree fittings though. 45 degrees from the pump to the CPU block, and then to the GFX block and to the chipset. But chipset to chipset to mosfet to mosfet will be mainly 90 degrees.
 
Makes me want to dust off my Aquastream and see the delta from running a DDC1 w/ alpha cool top. Next on the list is to see if I can tolerate 8mm ID push to fit.
 
Is there any rough guestimation maths we can use to work out flow rates?
Click to expand...

Actually, depending on your skill at a stopwatch you should be able to do damn good measurements.

Flow is a volume over time. We will measure and calcultate the volume of a piece of our tubing and mark it, then time a bubble moving from the beginning of the volume to the end and thus will know how much (the volume) moves in what time.

you need -

A measured out length of tubing in YOUR system in which the ID does not change. An existing length or splice in a section temporarily (this will affect the measurement but only by a very tiny amount)

A stopwatch or watch with sweep second hand

A flexible (bendy) straw or length of small diameter tubing (like for IVs).

Measure and mark a length of tubing in your system, the longer and straighter the better. Preferably horizontal but thats may be difficult. If you are serious splice in at least 3 feet of tubing you can lay horizontal on a table or platform next to the computer and carefully measure and mark (before you install it) some known distance as long as practical. (in high flow systems our bubble will be moving right along so for an accurate measurement its the timing part that is hard to do)

Take your inside diameter of your length of tubing and calculate the cross sectional area which is 1/2 the diameter(radius) squared times pi (3.141)

Now multiply the cross sectional area by the length you measured out to get the volume. keep the units the same mm or inches dont matter I give you the conversions below.

use the straw or tubing to inject a few air bubbles into your res or fillport, lock onto a bubble and time the amount of time it takes to pass through your marked section of pipe.

flow = a volume/per unit time you have the numbers now just convert them into whatever you need.

1 US gallon = 231.000001 cubic inches
1 liter = 61.0237441 cubic inches

The bubble has some buoyancy that affects its speed through the tubing, if you catch a bubble going "down" your result will be a little low, bubbles going up result a little high. Sideways is good but it will probally bump the top to the tube but if you have any decent flow these errors caused by using an air bubble should be small. Small bubbles are best.

( I am slighty tipsy due to some "medication" for a sore tooth, there may be a minor error somewhere above but I know if there is one you guys can figure it out in spite of it. )
 
LOL I would dealy love to get crocked with "the watercoolers" but I am worried bout the knife fights that would break out over the ratio of "anti freeze" to "coolant" for the optimal "mix"
 
BillParrish said:
Actually, depending on your skill at a stopwatch you should be able to do damn good measurements.

Flow is a volume over time. We will measure and calculate the volume of a piece of our tubing and mark it, then time a bubble moving from the beginning of the volume to the end and thus will know how much (the volume) moves in what time.

( I am slighty tipsy due to some "medication" for a sore tooth, there may be a minor error somewhere above but I know if there is one you guys can figure it out in spite of it. )
Click to expand...

That must be some good shit you got! How about just sticking one tube in a bath tub filled with water and measuring the output of your system going via the other tube into a graduated cylinder. Time for one minute intervals times 10 times, kick the high and low tests, and finally average the balance to get your LPM. Sounds easier than adjusting your setup to the angle of the dangle. ;)
 
The last time I took my computer into the bathroom , my dog looked at me funny.

Besides the bubbles are fun /hic
 
Call me pragmatic, but something has always disturbed me about this thread. If Cathar was wrong before what makes him right now?
 
What, specifically, was I wrong on before, that is relevant to this thread?
 
About the bigger tubing sizes being the best that your other research concluded a few years back. And now I wonder what else might be evident, but not accounted for.
 
I'm sure Cather answered that somewhere regarding the availabilty of better pumps now than in "previous" eras.:p

Just not sure where I saw the specific statement: here or XS, or perhaps in the Twilight Zone.:confused:
 
I think top nurse is one of those people who don't take into the factor of advancements.

Okay, 50 years ago, if you said volcanos and earthquakes are caused by plate movements, you'd be laughed out of the building.

However now, it is a theory that is widely accepted. But with your train of thought, I should say "well, if they were wrong 50 years ago, what makes them right now?"

Fact is, years ago we didn't have fancy blocks that work well with low flow systems. You had the Maze 3, a block nearly worthless in a low flow system, now you have fuzions and apogee GT's and all your aqua computer stuff.

Years ago you didn't have PA120.3 radiators that work well with low flow systems, you had car radiators that needed a ton of flow and pressure just to get water through the damn thing.

Technology changes Top Nurse. Cathar was right about low flow 3 years ago, and now he is right again just due to the fact that technology has changed. Low flow 3 years ago was garbage, now it is just a little worse than high flow systems. He was never wrong about tubing sizes impact on temperatures. I bet you if he did the same test, with the same technology as last tests, he would get the same results.
 
Top Nurse said:
About the bigger tubing sizes being the best that your other research concluded a few years back. And now I wonder what else might be evident, but not accounted for.
Click to expand...

Uh, how is that wrong, even now? All that has changed is the scale of the differences. Bigger tubes are still the best, but the question is, "By how much?".

Seriously, I have absolutely no idea where you're going with this, other than as a perverse demonstration of defective logical reasoning.
 
The only blocks that ever demonstrated superior performance with small-bore tubing were those where the tubing size determined the jet velocity in an impingement action.

More modern blocks nowadays use separate internal accelerator plates or nozzles, so rather than paying the restriction penalty of small bore tubing for an entire system, the restriction is localised to where it is needed. With that development, it is always the case that larger bore tubing will offer less restriction, and by nature, higher flow rates for the same amount of pumping effort.

All that matters is the scale of it. Today's blocks and radiators perform well enough at moderate flow rates that the use of larger bore tubing doesn't present us with any major performance improvement. The improvement is still there, just minimal.

How has anything been wrong here? In the past, or now?
 
Also, after rereading the original post, perhaps the most important statement made by the OP (as I interpret it) is that as long as you can obtain sufficient flow, tubing size means very little.

Which makes sense. Flow is flow. Tubing size effects flow only from the increased pressure drop in the system. Everything else being equal, bigger tubing will improve flow and cooling ability (both only a certain point). Since modern pumps can produce sufficient flow rates for a WC'd computer relatively independent of tubing size, the tubing size starts to become less important. Without the pump itself dumping a large amount of heat into the loop.

Cather: sound about right?
 
You must log in or register to reply here.
Back
Top