Feed back on my design..

[Tachyon]

I'm not really interested in debating the actual hardware at this time, just my design. I'd like to discuss the why I'm doing it this way to see if it's sound. So in lue of a thousand words ..... I give you this ...

[BGP Spook]

You appear to be running three separate loops, each with it's own pump.

Any specific reason why?

Usually, it is simpler and cheaper to run one long loop in series with little lost to cooling performance. There is usually less than 1 C delta for the water coming out of any given water block.

Speaking of water blocks, I don't think you mentioned what water blocks you would be using. That can have an effect on how you would want to run you loop. Like if all you used was Storms.

Also, I wouldn't be sizing down the tubing from 1/2" going into the pumps to 3/8" coming out of the pumps. The only good reason I can see for doing that would be if all my water blocks were 3/8" but I would try and consider other options.

Your illustration suggests you are considering a chiller rather than a radiator, but you don't list any models.

You probably don't need to WC the NB and SB, unless you are very severely violating their integrity(%20+ overvolt?).

[Tachyon]

Why 3 independent pumps.
Well two reasons .. first I wanted to have the coolest coolant available to each of the critical devices. Second - since water, like electricity, follows the path of least resistance, I did not want to give it a chance to favor one device over another for any reason. In a design where you have a header or "Y" adaptor there is nothing stopping some or all the coolant from flowing down a single path.

Speaking of water blocks....
I'm really liking the design and results I'm seeing on the new D-Tek Fusion for the CPU. On the GPU's probably going to be danger den unit (when available) NB & SB ..hmm hadn't really decided .. they're not really that critical.

....sizing down the tubing....
Here is my thinking here - you have 2 or in my case 3, 3/8 coolant lines each with a fixed flow rate. It's pulling out of the cool supply rez - thur the loops to the warm rez tank. Now - what size tube/s would you use for the lines going from the warm tank to the cool tank via what ever I use to remove the thermal energy with. Answer: in my case 3 loops x 3/8" (9/8ths or 1 1/8th) or I'm ok to round down to 1" with the understanding that there is going to be a slight flow increase in those lines. In a single loop system where you have 1/2” or 3/8” tubing throughout it’s a none issue since you’re minding the conservation of additive flow rates. (there are none to add!) But in a multi-looped system or one where you’ve divided the flow some how … I would think that to be efficient you’d need to mind those additive flow rates. What I do not understand is when people take a 1/2" supply line and divide it into two 1/2" lines via a "Y" (or worse yet a "T"). From a total flow volume and rate stand point this would seem to be problematic or at the very least inefficient. A 1/2” input to two 1/4” outputs “Y” adaptor is what I’m talking about here for example. Am I way off here or is this just not an issue? Has this been tested before?

...you are considering a chiller rather than a radiator...
Well I've got some ideas there that I'm not done messing with in my brain yet. But I've just read about the Switftech chiller with it's performance levels and it looks interesting.
Ever notice how your basement floor is always cold .... mine is .... and it's < 8' below me... Why not place a radiator/fan down on the basement floor to utilize the lack of thermal energy to remove some from my system. In a sealed system pump heads are irrelevant (theoretically) The pump is just acting as a recirculation pump. In this scenario anything could be used as it’s “in the basement”. Like a full sized automotive radiator with a real 12vdc fan on it .. ok way over kill …. But you get my drift. You could use say a automatic trans-cooler with integral cooling fan quite nicely.

Tach -

[BGP Spook]

Lets see.

Originally Posted by Tachyon

Why 3 independent pumps.
Well two reasons .. first I wanted to have the coolest coolant available to each of the critical devices. Second - since water, like electricity, follows the path of least resistance, I did not want to give it a chance to favor one device over another for any reason. In a design where you have a header or "Y" adaptor there is nothing stopping some or all the coolant from flowing down a single path.

I am not sure you understood my suggestion in my last post, I suppose I was not being clear on it.

In a loop set up in series, the temperature difference on either side of any given component is almost negligible, assuming your loop has good flow rates.

If you ran the loop in series as follows, Cool rez>CPU>GPU1>GPU2>NB>SB>Warm rez, the difference in water temperature between the beginning of the loop and the end of the loop would be maybe, maybe 5 C if you had very poor flow.

Do some searches on these forums, they are a wealth of information about the details of WCing.

Now if you still want to run independent parallel loops then I will drop it, but I think you would be better off running your loop in series. Run the numbers, you might be surprised at how much energy water can take before it shifts 1C.

Originally Posted by Tachyon

Speaking of water blocks....
I'm really liking the design and results I'm seeing on the new D-Tek Fusion for the CPU. On the GPU's probably going to be danger den unit (when available) NB & SB ..hmm hadn't really decided .. they're not really that critical.

I will restate that the NB and SB probably don't need that kind of cooling unless you are seriously abusing them.

The important thing to know about the D-Tek Fusion is it is jet-impingement. That means reduced flow rates, although the Fusion claims to have fair pressure drop for a jet-impingement block.

Originally Posted by Tachyon

....sizing down the tubing....
Here is my thinking here - you have 2 or in my case 3, 3/8 coolant lines each with a fixed flow rate.

It's pulling out of the cool supply rez - thur the loops to the warm rez tank.

Now - what size tube/s would you use for the lines going from the warm tank to the cool tank via what ever I use to remove the thermal energy with. Answer: in my case 3 loops x 3/8" (9/8ths or 1 1/8th) or I'm ok to round down to 1" with the understanding that there is going to be a slight flow increase in those lines.

I think by starting at the run between your warm and cool rez you may be placing priority at the wrong end of you loop, from a design justification stand point.

Better to start where the action is, that is the water blocks and the pumps.

Originally Posted by Tachyon

In a single loop system where you have 1/2” or 3/8” tubing throughout it’s a none issue since you’re minding the conservation of additive flow rates. (there are none to add!) But in a multi-looped system or one where you’ve divided the flow some how … I would think that to be efficient you’d need to mind those additive flow rates.

What I do not understand is when people take a 1/2" supply line and divide it into two 1/2" lines via a "Y" (or worse yet a "T").

From a total flow volume and rate stand point this would seem to be problematic or at the very least inefficient. A 1/2” input to two 1/4” outputs “Y” adaptor is what I’m talking about here for example. Am I way off here or is this just not an issue? Has this been tested before?[/quote]


I would argue that is even less efficient to handicap a loop(s) by undersizing any portion of the tubing than it is to use a Y or T.

Again, plenty of good sources if you do a couple of searches.

Originally Posted by Tachyon

...you are considering a chiller rather than a radiator...
Well I've got some ideas there that I'm not done messing with in my brain yet. But I've just read about the Switftech chiller with it's performance levels and it looks interesting.

I understand how that is, I have been mulling a case design around in my head for more than a year now and only have it a third finished. No rush.

Originally Posted by Tachyon

Ever notice how your basement floor is always cold .... mine is .... and it's < 8' below me... Why not place a radiator/fan down on the basement floor to utilize the lack of thermal energy to remove some from my system.

Don't have a basement, but I walked down you train of thought. You may be surprised where you end up. If you had a big enough basement it would be possible, but keep in mind that earth is a wonderful insulator.

You will almost certainly end up with a large volume of air to use as a heat dump but if you leave your computer on you will eventually be no better off than if you had stuck with more traditional methods.

Originally Posted by Tachyon

In a sealed system pump heads are irrelevant (theoretically) The pump is just acting as a recirculation pump. In this scenario anything could be used as it’s “in the basement”. Like a full sized automotive radiator with a real 12vdc fan on it .. ok way over kill …. But you get my drift. You could use say a automatic trans-cooler with integral cooling fan quite nicely.

I don't think your first statement is entirely correct. In reality, you pump still has quite a task just keeping the water flowing within a loop inside one's case. Adding a ten foot vertical probably won't help temperatures any. The less tubing the better.

-----------------
It seems to me that you still haven't mentioned the entire story, yet.
I get the impression you already have plans (and parts) in place or almost so.

Care to enlighten my sagging mind.

[Tachyon]

[to shake things up - in reverse order this time]

I have no parts at all that lock me into any design at this point. Just this design that I've become "engineeringly" comfortable with. It's all in my head ... (that's what she keeps telling me as well)

when is pump head not a pump head?
Consider this, an electric motors sits on a table next to a 10' piece of linear gear. This linear gear poses no load on the motor while sitting next to it. Now the motor starts to press this linear gear straight up, every inch adding to a load presented to the motor from the weight of the linear gear it's pushed vertical. Eventually the motor will stall due to the inability to "lift" any more gear weight. (say 10' of linear gear) Now ... lets take this 10' section of linear gear, wrap it around a wheel and place the motor on it. The will still have deal with inertia [or the lack there of] but it will not stall. Given a few seconds or minutes it would reach the motors spin rate minus some amount due to friction. In a water scenario a pump head measurement it taken with a "linear gear". A open ended tube with which the pump will see how much fluid it can push vertical. At some point the pump will no longer be able lift any additional fluid weight. In a closed loop, it'd be taking advantage of the returning fluid’s weight to counter act what would be the "head" or pressure side of this picture. The pump will take a bit to get the water "spinning" in our loop but eventually it will spin at the pump's rate minus some flow resistance. All “my” theory but to you follow my logic?

...but if you leave your computer on....
that was the one unknown in my thinking. How fast I could heat the basement? I've kept the idea alive for now because of how well this technology has worked. Albeit on a much larger scale than my basement.

...handicap a loop(s) by under sizing any portion of the tubing...
hmmm I'm not really "reducing" the tubing size as much as I'm giving the pumps unrestricted access to supply. It’s a 3/8” cooling system. I just have 1/2” supply lines to the pumps. Why 3/8”? In my design I have 3 pumps & 3 loops worth of volume. I didn’t want to have to think about 1 1/2” lines from the warm rez -> radiator -> cool rez. (1/2” times 3 = 1.5” total volume)
I really dig those Laing pumps. From an engineering stand point they’re nearly perfect. (ok well that input line was a real Homer Simpson) and people here have already shown that a straight in supply with no restrictions (read 1/2 supply line) that these little beggars can really pump it real good .... [wait - write that down I think we have a song here - pump, pump it jam, pump it up.... ] oh yeah.

...NB and SB probably don't need that kind of cooling ...
On the eVGA reference i680 board they've (nVidia) have designed a heat pipe that runs from the SB to the NB and the NB has a fairly good sized fin area *and* it's own fan. Somebody thought it might be a good idea to cool it better then the plain-ole HS or HSF. Then again that hardware might just be eye candy or "wow" factor. As I do not have not gotten any hardware yet... I can't say but this is why I included it on that loop.

...you didn't understand my suggestion ....
No, I think I did ... I just might be under estimating the ability of water to absorb that much thermal energy. You know, I was the only one in high school physics that argued against the theory that warm water freezes quicker then cool water does due to the molecules being more mobile. I'm looking at it from an over all thermal energy level stand point of view. You still have to remove "X" amount of thermal energy to get the water to freeze. But what you're telling me, and please anyone jump in and choose your sides here, is that water is efficient enough at absorbing thermal energy that in our little thermal engines none of the individual parts (CPU, GPUS, Chipset) generate enough thermal wattage to raise the coolant temps appreciably in one, series looped, circuit? So - someone could take the radiator out of the loop and run the system for a short period of time before the coolant temps rose appreciably. Correct?
In my current design - guessing and stabbing in the dark, what would you guess the deltaT be between the two rez tanks assuming an average 50% load on the GPU's and CPU? (I realize there are a lot of variables - guess)

I can certainly grab a hold of the "point of diminishing returns" here. It's one of the reason's I'm not spec'in this system with a quad-core. Not much to do for a "double the cost" investment. What I'm learning here [and exactly why I wanted to engage this forum] is that - sure you can have a triple looped system, but at 2-3 times the cost I'll not see the requisite raise in performance. Or at least lower temps in any of the individual heat sources. I hope this is your point and that it has been realized in "real life" experiences. I do not think I've seen anyone do comparative tests of a single looped system to a system with individual loops for each one of the major heat sources.

[BGP Spook]

If I may suggest it, I try to separate every couple of sentences with white space as it helps legibility. 250 word paragraphs with next to no white space give me a head ache.

Originally Posted by Tachyon

[to shake things up - in reverse order this time]

I have no parts at all that lock me into any design at this point. Just this design that I've become "engineeringly" comfortable with. It's all in my head ... (that's what she keeps telling me as well)

Are you an engineer?

I tend to think you aren't based on some of your descriptions(no offense intended)
but I want to ask anyway. You could be an electrical engineer trying to describe a dynamic mechanical problem in terms you understand.

Regardless, I would call what you describe above being "mentally comfortable" with an idea or method. You have sat down and thought about this for lengths of time and are satisfied that you have covered all or nearly all the angles.

Originally Posted by Tachyon

when is pump head not a pump head?
Consider this, an electric motors sits on a table next to a 10' piece of linear rear.

This linear gear poses no load on the motor while sitting next to it.

Now the motor starts to press this linear gear straight up, every inch adding to a load presented to the motor from the weight of the linear gear it's pushed vertical.

Eventually the motor will stall due to the inability to "lift" any more gear weight. (say 10' of linear gear)

It took me a second read to visualize what you were trying to illustrate.

I understand what you are implying.

I think your example may be flawed, the motor would stall initially rather than once it got to a certain height.

The force of the mass of the linear gear acting on the motor wouldn't change just because it was elevated a short distance.

The acceleration of gravity is constant for small changes in height.

It would, however, change slightly from the acceleration cause by the motor although the change would be negligible for our purposes.

Originally Posted by Tachyon

Now ... lets take this 10' section of linear gear, wrap it around a wheel and place the motor on it.

The will still have deal with inertia [or the lack there of] but it will not stall.

Given a few seconds or minutes it would reach the motors spin rate minus some amount due to friction.

In a water scenario a pump head measurement it taken with a "linear gear".

A open ended tube with which the pump will see how much fluid it can push vertical.

At some point the pump will no longer be able lift any additional fluid weight.

In a closed loop, it'd be taking advantage of the returning fluid’s weight to counter act what would be the "head" or pressure side of this picture.

The pump will take a bit to get the water "spinning" in our loop but eventually it will spin at the pump's rate minus some flow resistance.

All “my” theory but to you follow my logic?

I understand you theory but I am sure not all of your assumptions hold out.

In truth I don't fully understand all the vagaries of fluid Dynamics.

For the pumps you are talking about using I think you may be disappointed.

That is my real concern, that your pumps will be insufficient.

I would add that you are neglecting the effect of friction which one can generally do in mental exercises as long as they are factored in later.

Most people who want reasonable flow rates put one or two of the pumps you would be using on a single loop that only operates inside their computer with about 6'-8' of tubing and one or two blocks.

Having one pump per loop may not be enough if each of those pumps have to move the water 25'. (10' up +10' down+5' for routing)

There are ways of limiting this, example: have both rezes on the same upper floor, but the pumps will still be pushing water through more feet of tubing than the really needed to be.

Originally Posted by Tachyon

...but if you leave your computer on....
that was the one unknown in my thinking. How fast I could heat the basement? I've kept the idea alive for now because of how well this technology has worked. Albeit on a much larger scale than my basement.

The scale is what I am think will limit it, but maybe not.

Do some googleing and research it. Should always be the first step in a project.

If you look around hard enough I am certain you can find a "do it yourself" guide or an explanation on how it works.

Here is a source I found by googleing 'ground cooling.'

Originally Posted by Tachyon

...handicap a loop(s) by under sizing any portion of the tubing...
hmmm I'm not really "reducing" the tubing size as much as I'm giving the pumps unrestricted access to supply. It’s a 3/8” cooling system. I just have 1/2” supply lines to the pumps. Why 3/8”? In my design I have 3 pumps & 3 loops worth of volume.

I didn’t want to have to think about 1 1/2” lines from the warm rez -> radiator -> cool rez. (1/2” times 3 = 1.5” total volume)

With this thinking you are artificially limiting your performance.

Have you ever used a syringe?

It takes a lot of force to expel the contents of a syringe quickly.

If you took the same syringe and cut the part where it necks down off and tried to expel the same contents of the syringe quickly it would be very easy by comparison.

My point is, you will be limiting the performance of your pumps by sizing down the tubing on the output side of your pumps.

The only reasoning you have given for justifying this is that you don't want to use 1.5" tubing between your each rez.

You could use three 1/2" tubes you know and most WCing radiators come in 1/2" or 3/8" sizes anyway.

Furthermore, running radiators in parallel water flow should net slightly more efficient performance, provided that the flow through each rad is sufficiently turbulent.

A couple of threads with links on the subject. Worth reading.
http://forums.procooling.com/vbb/showthread.php?t=12697
http://forums.procooling.com/vbb/showthread.php?t=13792

Please ask questions about the results if you have difficulty understanding them.

Originally Posted by Tachyon

I really dig those Laing pumps. From an engineering stand point they’re nearly perfect. (ok well that input line was a real Homer Simpson) and people here have already shown that a straight in supply with no restrictions (read 1/2 supply line) that these little beggars can really pump it real good .... [wait - write that down I think we have a song here - pump, pump it jam, pump it up.... ] oh yeah.

I guess I am really just questioning your pump choice for what you seem to be talking about doing.

The MCP350 is a very good pump but it has its limitations.

Originally Posted by Tachyon

...NB and SB probably don't need that kind of cooling ...
On the eVGA reference i680 board they've (nVidia) have designed a heat pipe that runs from the SB to the NB and the NB has a fairly good sized fin area *and* it's own fan.

Somebody thought it might be a good idea to cool it better then the plain-ole HS or HSF.

Then again that hardware might just be eye candy or "wow" factor.

As I do not have not gotten any hardware yet... I can't say but this is why I included it on that loop.

It is your money, it is your loop, you already know my opinion.

It is up to you to decide.

Originally Posted by Tachyon

...you didn't understand my suggestion ....
No, I think I did ... I just might be under estimating the ability of water to absorb that much thermal energy.

The specific heat of water is about (4.181 watts * sec)/ ( gram),
with 1 gram = 0.997 ml of water for 25 C ambient, using this table.

Assuming we run a loop in series.

Say 50 ml of water per second (~3 liters a minute) and 100 watts of heat dump.

Where x is the change in the temperature of the water.
100 W =((4.181 J) / (1 g*C)) * ((1 g) / (0.997 ml)) * ((50 ml) / (s)) * x

x=~0.48 C

This represents a fair estimate of the likely difference between the "cool side" and "warm side" of water block of a high heat dump component.

33.3 ml/s =~ 2 liters a minute.

Most systems run closer to 4 - 6 liters a minute, and most water blocks are designed to operate at those flow rates.

400 watts of heat dump is a huge amount, and I consider it a gross overestimate of your likely heat dump.


Where x is the change in the temperature of the water.
400 W =((4.181 J) / (1 g*C)) * ((1 g) / (0.997 ml)) * ((33.3 ml) / (s)) * x

x=~2.86 C

That doesn't mean that the water on the "warm side" of your loop will be ~3C above ambient temperature, that is a whole other set of equations.

What that number means is the difference between the temperature of the water on the "cool side" of the loop vs the "warm side of the loop" will probably be less than 3C, assuming any kind of reasonable flow rate and anything but an insane heat dump.

Originally Posted by Tachyon

You know, I was the only one in high school physics that argued against the theory that warm water freezes quicker then cool water does due to the molecules being more mobile.

I'm looking at it from an over all thermal energy level stand point of view.

You still have to remove "X" amount of thermal energy to get the water to freeze.

But what you're telling me, and please anyone jump in and choose your sides here, is that water is efficient enough at absorbing thermal energy that in our little thermal engines none of the individual parts (CPU, GPUS, Chipset) generate enough thermal wattage to raise the coolant temps appreciably in one, series looped, circuit?

So - someone could take the radiator out of the loop and run the system for a short period of time before the coolant temps rose appreciably.

Correct?

In my current design - guessing and stabbing in the dark, what would you guess the deltaT be between the two rez tanks assuming an average 50% load on the GPU's and CPU? (I realize there are a lot of variables - guess)

See previous calculations.

The temperature difference between the water and the ambient air temperature is very, very much dependent on how you remove heat from the loop.

Such as the number, size, and quality of the radiators you use, and also the air and water flow through them.

Originally Posted by Tachyon

I can certainly grab a hold of the "point of diminishing returns" here.

It's one of the reason's I'm not spec'in this system with a quad-core.

Not much to do for a "double the cost" investment.

What I'm learning here [and exactly why I wanted to engage this forum] is that - sure you can have a triple looped system, but at 2-3 times the cost I'll not see the requisite raise in performance.

Or at least lower temps in any of the individual heat sources.

I hope this is your point and that it has been realized in "real life" experiences.

I do not think I've seen anyone do comparative tests of a single looped system to a system with individual loops for each one of the major heat sources.

I am a little tired and I need to get ready to leave soon but I think I know what you are talking about.

And if so, then yes, that is kind of my aim.

You won't see a linear relationship between your expenditure and your return for what you seem to be planning vs what I have been suggesting.


---------------------------
And I think this makes it into one of my top ten longest posts on these forums.

[Tachyon]

Yeah .. I didn't think I could get you to ignore that part of the linear gear analogy. So ..ah .. ignore that part of the gear plz.. .. yes I know a classical 10' linear gear the entire length's weight would be present at all times ... I was hoping you'd make the jump with me once I made the fluid part of the analogy. The fluid that the pump has not placed in the vertical tube is not part of the equation.

An easy test would be to set up a pump head test .... then increase the head tube by 100%. Fill it completely with fluid. Attach the top end to the pump's intake and see if it can move the fluid around the loop. Loop must stay in the vertical orientation.
I know it will..... my point.

BTW- the basement floor idea is just a interesting side thought for me.. I'm really am thinking along the lines of a single radiator .... like a GT stealth 360 Blackice.

ah .. you could say I have a better the average understanding of mechanical and electrical engineering. No degrees - but ... plenty of practical experience. Yes "mentally comfortable" was my first choice but I liked the "engineering" flavor that best described my feelings.

Sry to hear your opinion on the Laing pumps. What pump do you like for this application?

I was glad to see your thermal calculations for this. And I did assume the deltaT we were discussing was from warm to cold and had nothing to do with ambient. What is your background if I might ask.

My wife is vet technician, so I've seen my share of syringes. For me they come in handy as a fine point oiler.

I will look over the radiator flow rate threads you provided. Looks to be good reads. That part of my design is still unfocused. But I'm not worried about it at this point since there are plenty of good solutions out there.

Question: “the D-Tek fusion is a jet-impingement design decreasing the flow”. Wouldn't a single pump dedicated to just that device (one of my 3 loops) be best able to deal with this back pressure as opposed to this one pump pushing against the CPU and two GPU's? So a larger pump might be necessary on a single loop series system. But you could get away with smaller pumps on a parallel system.

I’ve not ignored the friction of this system nor the back pressures that the various blocks might offer. I just do not have the field experience to be able to quantify it into my thinking at this point.

Greatly distilled (yes these have been long posts but fun none the less) you’re saying don’t over engineer it. A single 1/2” series loop from a larger pump to the CPU -> GPU1 -> GPU2 -> a radiator -> rez (no need to have two reservoirs now) is what has been proven to be “enough” to get the job done.

[Tachyon]

Da BEARS !!!! GO BEARS !!

sry - took a bit to reply .... celebrating ...... GO BEARS !!

[BGP Spook]

Originally Posted by Tachyon

Yeah .. I didn't think I could get you to ignore that part of the linear gear analogy. So ..ah .. ignore that part of the gear plz.. .. yes I know a classical 10' linear gear the entire length's weight would be present at all times ... I was hoping you'd make the jump with me once I made the fluid part of the analogy. The fluid that the pump has not placed in the vertical tube is not part of the equation.

Don't worry about it.

I understood the analogy but was just pointing out a flaw which needed addressing.

No hard feelings.

Originally Posted by Tachyon

BTW- the basement floor idea is just a interesting side thought for me.. I'm really am thinking along the lines of a single radiator .... like a GT stealth 360 Blackice.

Originally Posted by Tachyon

ah .. you could say I have a better the average understanding of mechanical and electrical engineering. No degrees - but ... plenty of practical experience. Yes "mentally comfortable" was my first choice but I liked the "engineering" flavor that best described my feelings.
...
What is your background if I might ask.
...

I am a fourth semester year engineering student.

I have a variety of technical experience.

I have spent the last three years reading about and researching water cooling and the last two years with my computer being water cooled.

Originally Posted by Tachyon

Sry to hear your opinion on the Laing pumps. What pump do you like for this application?

I fear I may have not been clear.

The MCP350 is well suited to internal case use, mainly because of its performance relative to its size.

But for the basement project?

Oi, I don't know where to begin for that.

For general usage, I am very cheap.

You can see some of my recommendations if you read a couple of the threads.

Originally Posted by Tachyon

I will look over the radiator flow rate threads you provided. Looks to be good reads. That part of my design is still unfocused. But I'm not worried about it at this point since there are plenty of good solutions out there.

Be sure to review the PA series curves.

Marci has been gracious enough to provide links and the PA series are excellent radiators.

Originally Posted by Tachyon

Question: “the D-Tek fusion is a jet-impingement design decreasing the flow”. Wouldn't a single pump dedicated to just that device (one of my 3 loops) be best able to deal with this back pressure as opposed to this one pump pushing against the CPU and two GPU's? So a larger pump might be necessary on a single loop series system. But you could get away with smaller pumps on a parallel system.

When people get large multi block loops in series they often will double up on their pumps as well.

Say something like, T-line or rez>pump1>radiator>pump2>rest of loop.

By running identical pumps in series you can basically double the head pressure causing an increase in flow rates.

While if you run them in parallel you get about a 50% - 60% increase in flow rates.

By running two pumps in series you can overcome the difficulties of most any loop in series.

Originally Posted by Tachyon

I’ve not ignored the friction of this system nor the back pressures that the various blocks might offer. I just do not have the field experience to be able to quantify it into my thinking at this point.

Bigger tubing will offer less friction than small diameter tubing.

Avoid sharp turns, U's, right angles, in your tubing layout.

Run the shortest simplest route from your pump back to your pump.

As for water blocks...some water blocks offer more resistance than others.

The Apogee, MCW60002, and the Maze 3 or 4 are good examples of some pretty free flowing water blocks.

The Alphacool NexXxoS XP, the Storm G4 or G5, and the MP-05 SP are good examples of fairly restrictive water blocks.

A worth reading, if controversial review.

Which might bring you to question your water block choice.

Originally Posted by Tachyon

Greatly distilled (yes these have been long posts but fun none the less) you’re saying don’t over engineer it. A single 1/2” series loop from a larger pump to the CPU -> GPU1 -> GPU2 -> a radiator -> rez (no need to have two reservoirs now) is what has been proven to be “enough” to get the job done.

That pretty much sums it up.

If you want to get into the details and understand why it is enough, which I recommend why be dogmatic, then I recommend you do more research and continue to ask questions.

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I am very tired right now and need to sleep.

I haven't slept very well the last couple of days for one reason or another.

I would like to continue this discussion after you have read about some of the "recent" developments in water blocks and radiators.

You may change your mind on some things, particularly on the importance of the one's choice of radiator and fans.

I know, seems ironic that the biggest(or next to biggest) controlling factor in water cooling performance is actually the air cooling component of it.

Such is life.

BTW, congrats on the Bears winning.