Smartest way to share a pump between 2 systems? (MM duality)

[JavaGeek_Boston]

Hello All,
I bought a MountainMods ascension duality which supports two motherboards. I have a 2 systems, 1 for work (Linux) and 1 for gaming (Windows). The gaming system is liquid cooled. I'd like to put the work system into my cooling loop.

How can I setup a pump and some fans on a radiator so that they are powered on if either system is powered on? I'd like to set it so that 2 molex devices power on if either power supply 1 or power supply 2 is powered on.

I thought of two options and wondered if the forum folks had better ideas or inputs on these:

Option 1:
Reverse Y-adapter. Instead of taking one molex input and splitting it to two devices, I was going to have 2 molex inputs and one output. I am not too experienced with these things.

Will the voltage change if both PSUs are powered on?

For simple devices like fans and water pumps, is a voltage increase a cause of serious concern? I have a Liang D5 pump that already has a resistor built-in. If I had the pump set to the lowest speed, wouldn't a voltage increase just increase the speed a bit?

Option 2:
3rd PSU with relay. Does anyone know how I can setup a device to power 2 molex devices (my pump and fans) if either PSU is powered on? I've seen such devices for one power supply for AC pumps and have seen something similar in the woodworking world for dust collectors. Does anyone have any idea if something like that exists that can turn itself on if PSU1 or PSU2 is powered on and be smart enough to shut itself down when both are powered off?

Option 3+: Does anyone have better ideas?

Any input is greatly appreciated

[xaxis]

Hello All,
I bought a MountainMods ascension duality which supports two motherboards. I have a 2 systems, 1 for work (Linux) and 1 for gaming (Windows). The gaming system is liquid cooled. I'd like to put the work system into my cooling loop.

How can I setup a pump and some fans on a radiator so that they are powered on if either system is powered on? I'd like to set it so that 2 molex devices power on if either power supply 1 or power supply 2 is powered on.

I thought of two options and wondered if the forum folks had better ideas or inputs on these:

Option 1:
Reverse Y-adapter. Instead of taking one molex input and splitting it to two devices, I was going to have 2 molex inputs and one output. I am not too experienced with these things.

Will the voltage change if both PSUs are powered on?

For simple devices like fans and water pumps, is a voltage increase a cause of serious concern? I have a Liang D5 pump that already has a resistor built-in. If I had the pump set to the lowest speed, wouldn't a voltage increase just increase the speed a bit?

Option 2:
3rd PSU with relay. Does anyone know how I can setup a device to power 2 molex devices (my pump and fans) if either PSU is powered on? I've seen such devices for one power supply for AC pumps and have seen something similar in the woodworking world for dust collectors. Does anyone have any idea if something like that exists that can turn itself on if PSU1 or PSU2 is powered on and be smart enough to shut itself down when both are powered off?

Option 3+: Does anyone have better ideas?

Any input is greatly appreciated

I've got to go outside and take care of some urgent stuff but when I come back in later I'll try and help you with this. I'm only saying something now because I want to make sure that you DO NOT DO ANYTHING UNTIL YOU KNOW WHAT YOU'RE DOING!!! If I read some of the things you were thinking about correctly (or at least the way you wanted to implement them) you are at the very least going to damage your equipment! Hopefully someone else can advise before I get back... just DON'T DO ANYTHING PLEASE... NOT YET!

[JavaGeek_Boston]

I appreciate the help. Obviously, this is the sort of thing that you test first before you act. I was planning on building the reverse Y adapter first and testing with a multi-meter.

However, if someone has a better idea, it may save some time and is certainly greatly appreciated. Surely I'm not the first guy who has tried this. I'd certainly love to learn from others' expertise.

Thanks again,
Steven

[dengyong]

Just buy another pump. You spent all that money for your other parts so don't half ass the cooling.

[Utnorris]

Ok, they way I would suggest doing it is to use a separate PSU for the water cooling gear and use a relay powered by a molex plug from each one of the systems. However you would need to do a resistor in line on each of the 12v lines coming from the computers to prevent 12v power flowing back to the powered off system. You will need to look that part up, but I am pretty sure it would work. Essentially what you are doing is using a molex connector from the system PSU to energize a relay that will then connect the ground wire and green wire on the water cooling PSU telling it to turn on, sort of like when you want to use a PSU to do a leak test without turning the MB on. The main concern here is preventing feedback from one system to the other which the resistors should do, I am just not sure of which ones to use.


Then you could use one pump, one res and one rad to cool the water blocks on each side, wouldn't matter if the computer was on or off, the water would still flow through the blocks. You could use the new Primochill Typhoon 3 instead of use "Y" adapters which would hurt your flow.

The other option of course is to just use a separate water cooling setup for the business machine. Depending on the gear you could use something simple like the Swiftech H2O-120 which is just two parts, even the H2O-220 is the same but with a dual rad. Very good systems and very simple and compact.

[MpG]

Yeah, a basic reverse-Y like you describe is a recipe for wrecking whichever PSU isn't on. You'll need to either set up a relay design (which will cost some money in parts), or wire in a handful of diodes (which will reduce pumping power), and neither is an optimal solution. Furthermore, since you want one pump to handle two loops, you're going to see reduced performance overall. Better to just grab a second pump.

Something like a CPX-Pro won't break the bank, doesn't need an aftermarket top, and will give the second loop more performance than you'd get from sharing the single pump across both loops.

[Utnorris]

Actually, if he uses the Typhoon 3 he won't. I went from 2 x MCP355's with XSPC tops, one in a GPU only loop and the other in a CPU only loop, both with a Thermochill PA120.3, to the new Typhoon 3 which is just a res and MCP655 pump for dual loops and just in leak testing I can tell that I am actually getting better flow than I did before, even with the pump set to just 2 or 3 on the speed control. Seriously, it is a pretty sweet unit.

But again, the main issue is getting it to switch on with each side. I just had a thought, don't do the relay, just do a toggle switch that will turn on the water cooling separately from the systems. That way you don't need to worry about the relays, resistors and what not. You sit down to the computer, flick the switch and then turn on whichever system. Turn on the thermal shutdown in each of the bios just in case you forget to turn it on and you should be safe.

[rambler358]

I went from 2 x MCP355's with XSPC tops, one in a GPU only loop and the other in a CPU only loop, both with a Thermochill PA120.3, to the new Typhoon 3 which is just a res and MCP655 pump for dual loops and just in leak testing I can tell that I am actually getting better flow than I did before

Have you been able to record actual before and after flow rates yet?

[ILikeCosmosS]

If you want to share a pump, then get a the Rd-30. But the other option is typhoon III or Xspc dual ddc res/top

[Utnorris]

Have you been able to record actual before and after flow rates yet?

Oh I wish, but I need to pick up some more o-rings for my compression fittings to seal properly and I am currently at work till midnight. However, I believe Skinnee will have his review up later today and should have flow rates for you.

[JavaGeek_Boston]

Yeah, a basic reverse-Y like you describe is a recipe for wrecking whichever PSU isn't on.

Thanks for letting me know. I am interested in learning more. How would a reverse Y adapter (2 inputs to one output for the sake of providing power if input 1 or input 2 is switched on for those just joining us) cause trouble with the powered off PSU?

I believe what you're saying, I just want to learn as much as I can about these things so I don't do anything stupid in the future.

I appreciate your advice.

[Utnorris]

Since they would physically be connected you would be sending a 12v signal back up the molex to the un-powered PSU which could cause damage or various other issues.

[JavaGeek_Boston]

Just buy another pump. You spent all that money for your other parts so don't half ass the cooling.

Thanks for responding. I really don't want to half-ass the cooling...always good advice to do the cooling well. My livelihood revolves around being productive with powerful computers and I consider money spent on the cooling system money well spent.

I am worried about the fans as well. Hooking up a 2nd pump wouldn't guarantee that the fans would run without a 2nd power supply.

Off the topic...
Down the road, I was considering a 2nd pump just to quiet the system down (by turning the speed down) and protect against pump failure, but I'd prefer to have both running whenever either system is on and turned off when I turn off the systems.

Thanks for the advice!
Steven

[JavaGeek_Boston]

But again, the main issue is getting it to switch on with each side. I just had a thought, don't do the relay, just do a toggle switch that will turn on the water cooling separately from the systems.

Genius!!!

That's a really good idea. I wish I could automate it, but the toggle switch is simple and apparently much more effective.

I'd like to at least learn what I'd need for a relay with the toggle as my backup. Something tells me a toggle switch is in my near future.

I just wanted to say thank you and that you guys are great. You've generously provided a lot of good ideas quickly...more quickly than I can even physically respond to them. Hats off to you gentlemen (and ladies if I missed any).

[xaxis]

Okay, I'm back. I reread your post more slowly, it seems to me that you want to fire on the liquid cooling system components regardless of which system your actually going to be using and that you only plan on liquid cooling 1 system. Is this correct?

I don't understand why you want to do this. If your liquid cooled system is off, then why do you want your liquid cooling components to be on? Maybe I'm missing something.

[Utnorris]

Okay, I'm back. I reread your post more slowly, it seems to me that you want to fire on the liquid cooling system components regardless of which system your actually going to be using and that you only plan on liquid cooling 1 system. Is this correct?

I don't understand why you want to do this. If your liquid cooled system is off, then why do you want your liquid cooling components to be on? Maybe I'm missing something.

You are, he wants to cool both setups with one water cooling system. Essentially he would have one water system with two blocks, one for his gaming computer and the other for his Linux box.

[JavaGeek_Boston]

You are, he wants to cool both setups with one water cooling system. Essentially he would have one water system with two blocks, one for his gaming computer and the other for his Linux box.

Correct.

In case you were curious, I'm doing this for 2 use cases: testing distributed programs and Attention-Deficit-Disorder-esque switching between games and work.

The scenario is that I love to play games but I should be doing more work during the evenings and I built the dual system to make it more convenient. I'd like to be able to pause a game of Fallout 3, for example, work for 30 minutes, and resume it without waiting for the system to hibernate and reboot as I used to do when I had a dual boot system. I need a powerful system with as many cores as possible for programming and a powerful CPU + GPU for gaming.

Also, my other scenario is that I need to stress test my web applications, so I need a powerful multi-threaded client for JMeter (my load tester), a powerful server with a profiler running, and an isolated network as I don't want my response times polluted by competing network traffic or having the client on the same box as server.

I'd like to build 1 loop. My old loop had blocks on the CPU + GPU + HD + Northbridge + Southbridge. The NB + SB were probably overkill, so I want to remove them and have GPU1 -> CPU1 -> HD -> CPU2. -> RAD -> RES -> PUMP. For the linux box, I'd have 2 passively cooled GPUs as I'm not using 3D, just dual monitors and just WC the CPU.

Most days, I'll only be running 1 system, but lately work time has been encroaching on recreation time, so I'm hoping this will help me balance both.

[Utnorris]

So you want to cool 3 cpu's and 3 GPU's, is that correct?

[xaxis]

You are, he wants to cool both setups with one water cooling system. Essentially he would have one water system with two blocks, one for his gaming computer and the other for his Linux box.

Right you are. Missed that.

So do you ever plan on cooling both systems simultaneously? If not and you only planned on cooling one at a time (that is only 1 is turned on at a time), I know where you can get some 4 way pneumatic ball valves that would create a pretty nifty twist. That is, you turn on system A) and the loop would automatically segregate your cooling to that system and vica versa.... Fun stuff.

[Utnorris]

I think he wants to run them at the same time every now and then, but usually by themselves. My concern will be the cooling power of the rad, I think you will need to add to it depending on what you already have. Let's see a list of what water cooling you have and what exactly you want to be cooled and separate them into system 1 and system 2.

[Vapor]

My vote goes for a push/pull setup with the fans: one system's PSU covers the pull, the other the push. And an always-on AC pump (or a DC pump on a smaller, laptop-like PSU--I have one in my kitchen for bleeding loops )

[Utnorris]

Only problem with is you would have half the fans not working and just causing restriction on air flow. Beter to have the entire water cooling setup on it's own PSU and either manually switch it on or use relays and resistors to power it on.

[Vapor]

Considering a radiator is already impeding the airflow, the amount of airflow restriction a powered-off fan provides is really small

Adding a powered-off fan to a radiator is like taking a loop with Koolance 350 or EK Supreme and adding a few feet in tubing or a 90degree elbow--a drop in flow may exist, but it's imperceptibly tiny and does nothing to the performance picture.

Reasons why I like the push/pull fan + always-on pump: no interaction required (ever) and cooling capacity increases when both systems are on (though not much, maybe 15%, probably just the right amount to 'take care' of a second system at idle).

[Utnorris]

But why not have the fans always on also? I imagine they would not make much noise and would draw less power than the pump.

[Vapor]

But why not have the fans always on also? I imagine they would not make much noise and would draw less power than the pump.

Matter of taste I suppose. I'm of the mindset that less noise is always better.

The PSU I was thinking of was this: http://www.coolerguys.com/840556088776.html ....which, rated at 60W, is good enough to handle a pump and fans (a lot of pump/fan combos at least), so it doesn't matter either way