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riesscar · ‎02-14-2014

Hello,

I am in the process of extending my current loop to include two GPU's, and I have a question regarding loop order. I know that loop order is -- according to many tutorials -- not important outside of the reservoir feeding directly into the pump in order to prime the system; however, my situation is slightly out of the ordinary and I think that it might matter with my setup.

Here is the situation:

I purchased a Swiftech Apogee Drive II, which has a pump mounted atop the cpu block. When I did so, I didn't consider the problem of gravity needed in order to prime the pump. So... I decided on the following workaround: I purchased a Monsoon Bay Res which has an integrated pump that I use in order to prime the second one on the Apogee Drive II. This solution worked well, and I have a simple but effective loop running right now that cools only the cpu. Now that I intend to add another radiator, two gpu blocks and a tube reservoir (in order to facilitate bleeding of air and a drain valve), I need advice on what order the loop should be designed with.

System Specs:

Case: Corsair 900d
CPU: i7 4930k
GPU: 2x EVGA GTX 780ti Superclocked w/ EK Original CSQ Blocks & EK SLI Bridge
RAM: 32GB Corsair Dominator Platinum 2133Mhz
MB: Rampage IV Black Edition
PSU: Corsair AX1200i

Watercooling Components:

Radiators: 2x Alphacool Nexxos UT60 480mm (1 Top Mounted and 1 Bottom Mounted)
CPU Bock: Swiftech Apogee HD (combined with pump to create the Drive II)
GPU Blocks: 2x EK Original CSQ Full Cover Water Block and Matching SLI Bridge
Reservoirs: Monsoon Series II Bay Res w/ D5 Pump and EK 250 Multioption Tube Res V3
Pumps: Swiftech m35x PWM and Swiftech MCP-655 PWM
Tubing: Primochill Clear Tubing G 1/4
Fittings: Bitspower
Coolant: Mayhem Blood Red Pastel
Fans: 8x Corsair SP120

Ok, so here is the reason that I am concerned about the order of the loop. I originally planned to go Bay Res (to integrated pump) --> Tube Res --> Bottom Rad --> GPU --> CPU (to integrated pump) --> Top Rad --> Bay Res

Then I started thinking about the fact that the water that travels through the GPU's will be heated by them before it goes into the CPU block, which I imagine will degrade cooling performance for the CPU. Additionally, I wondered if there is any benefit to having the reservoirs not feed directly into each other... keeping in mind that I have two reservoirs for the reasons mentioned above.

Now I am thinking of the following order:

Bay Res (to integrated pump) --> Tube Res --> Bottom Rad --> GPU --> Top Rad --> CPU (to integrated pump) --> Bay Res

Does anyone have a better setup idea, or is my original loop order ok (for aesthetics I would like to use my original plan, but not at the cost of cooling performance).

Please keep in mind that all of the parts have already been purchased, so there's no need to point out things that I should or should not have gotten. Also, I cannot run two seperate loops due to the priming issue of the m35x and the necessity of the MCP-655 attached to the bay res.

Thanks for any help that you can provide.

-Carson

Antronman · ‎02-14-2014

I would actually recommend mixing Mayhem's pastel with Koolance's coolant. because with Koolance, you can mix metals. For a block, I would recommend the EK Supremacy or XSPC Raystorm blocks.

Say hi to the next generation.

Peace is a lie, there is only Passion
Through passion, I gain strength
Through strength, I gain victory
Through victory, my chains are broken
The Republic of Gamers shall free me

riesscar · ‎02-14-2014

Antronman wrote:
I would actually recommend mixing Mayhem's pastel with Koolance's coolant. because with Koolance, you can mix metals. For a block, I would recommend the EK Supremacy or XSPC Raystorm blocks.

Hey Antronman,

I appreciate the response, but I can't help but wonder if you read my post. I actually wasn't looking for advice on coolant or blocks. As the thread explains, all of the components have been purchased. It is the loop order/design that I am looking for advice on, taking into account the concerns outlined in my post.

Thanks though,

Carson

BTW: the delta testing on different blocks would actually indicate that the Apogee HD is a better cooler than the two that you mentioned (particularly the XSPC Raystorm). Alphacool makes the best ones, but they are insanely expensive and the difference is minuscule. And with regard to coolant, Mayhem advises against your suggestion due to the fact that their coolant is designed to be used without additives... I was even told that a silver coil would be a bad idea. Even with Koolance liquid solutions, mixing metals is never a good idea... Koolance even says this 🙂

Arne_Saknussemm · ‎02-15-2014

Well you have it right in your first paragraph...order is unimportant except for the res before pump rule. You then go on to contradict that with the misunderstanding later of warm water from GPU feeding the CPU...

The loop as a whole comes to equilibrium with ambient temp and the difference in water temp before and after a block or a radiator in a loop with good flow is tiny. So you should just worry about designing a loop with the most clean lines of tubing...the least acute changes in direction for the flow..i.e. avoid angled fittings, weird doubling back tubes etc. Just concentrate on the problem of making sure res feeds pump and that you can get air out of the loop efficiently.

And yes you are right you should not mix metals to avoid corrosion...no coolant will prevent it only retard it at the cost of less efficient cooling. The best coolant is pure distilled or deionized water with a kill coil if you can't be bothered to change the water every now and then.

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riesscar · ‎02-15-2014

Arne Saknussemm wrote:
Well you have it right in your first paragraph...order is unimportant except for the res before pump rule. You then go on to contradict that with the misunderstanding later of warm water from GPU feeding the CPU...

The loop as a whole comes to equilibrium with ambient temp and the difference in water temp before and after a block or a radiator in a loop with good flow is tiny. So you should just worry about designing a loop with the most clean lines of tubing...the least acute changes in direction for the flow..i.e. avoid angled fittings, weird doubling back tubes etc. Just concentrate on the problem of making sure res feeds pump and that you can get air out of the loop efficiently.

And yes you are right you should not mix metals to avoid corrosion...no coolant will prevent it only retard it at the cost of less efficient cooling. The best coolant is pure distilled or deionized water with a kill coil if you can't be bothered to change the water every now and then.

Hey Arne,

Thanks as usual for the helpful info. I figured that the water maintains equilibrium, but I just wanted to make sure. One question though with regard to your advice on creating as little restriction as possible: When I do need to make a turn (whether 45 or 90), do you think it is better to just use the flexible tubing in order to turn (and risk a kink I guess), or would you suggest using a 90 degree rotary compression fitting (I have some from Bitspower). The 90 degree rotary compression fitting I have doesn't seem like it is going to result in much restriction, as the turn is not sharp.

This is the fitting:
(http://www.frozencpu.com/products/21723/ex-tub-2161/Bitspower_G14_Thread_38_ID_x_12_OD_90-Degree_Tri...)

Regarding coolant, I know that I should use distilled or de-ionized water with a kill coil -- and that I should use colored tubing if I want a colored theme -- but I am willing to sacrifice a little cooling efficiency and increase the frequency with which I have to drain and refill for the aesthetics of my theme. I know this may seem silly, but colored tubing really doesn't look the same as clear with a pastel coolant. Perhaps next time I'll design a build with a transparency theme :).

Thanks again,

Carson

Arne_Saknussemm · ‎02-15-2014

riesscar wrote:
The 90 degree rotary compression fitting I have doesn't seem like it is going to result in much restriction, as the turn is not sharp.

Yes that looks like a good solution! Good radius on the curve so I can't imagine it will harm flow to any significant degree.

The pure water thing I just mention...of course you go with what you want; the cooling difference will be minimal and the aesthetics count for a lot;)

Rust? rust is iron oxide 😛 Galvanic corrosion will start to happen instantaneously in any system of mixed metals where the coolant is based on water whether it is deionized or not and whether it has inhibitors or not...just a question of time....deionized water becomes ionized instantly on contact with metals dust etc. the reason your board will fry instantly if you pour deionized water on it..

ARNE’S GUIDE TO PC BUILDING HAPPINESS

ARNE'S GUIDE TO OVERCLOCKING HAPPINESS

kkn · ‎02-15-2014

i have a rad between GPU and CPU.
my setup is RES, PUMP, 420, 2x GPU's, 240, CPU, 360, RES.
pump have temp sensor in it self, and i have one in the loop ( inline temp ).
http://www.frozencpu.com/products/13163/ex-tub-891/Phobya_G14_Inline_Temp_Sensor_Coupler_-_2-Pin_711...

http://rog.asus.com/forum/showthread.php?23795-overkill&p=282195&viewfull=1#post282195

Antronman · ‎02-15-2014

Actually rust is not a big problem. You can mix metals with Koolance coolant because I believe it is deionized. The main reason why mixing block and rad metals is unadvisable is because if the water ends up carrying ions over from one type of metal to the other, it could kill your hardware.

Say hi to the next generation.

Peace is a lie, there is only Passion
Through passion, I gain strength
Through strength, I gain victory
Through victory, my chains are broken
The Republic of Gamers shall free me

riesscar · ‎02-15-2014

Antronman wrote:
Actually rust is not a big problem. You can mix metals with Koolance coolant because I believe it is deionized. The main reason why mixing block and rad metals is unadvisable is because if the water ends up carrying ions over from one type of metal to the other, it could kill your hardware.

Hey Antronman,

Thanks for the info. That makes sense to me, although it's been a while sense I've taken a chem class :). The point is moot though, as I have all of my metals synchronized just in case... at least there is no aluminum for sure!

-Carson

riesscar · ‎02-15-2014

Antronman wrote:
Actually rust is not a big problem. You can mix metals with Koolance coolant because I believe it is deionized. The main reason why mixing block and rad metals is unadvisable is because if the water ends up carrying ions over from one type of metal to the other, it could kill your hardware.

Hey Antronman,

Thanks for the info. That makes sense to me, although it's been a while sense I've taken a chem class :). The point is moot though, as I have all of my metals synchronized just in case... at least there is no aluminum for sure!

-Carson

900d Custom Water Loop