Pump placement - Dual Radiator setup

[sethmo]

Still gathering parts for my new setup, and am wondering about pump placement. I will have the following setup:

-Fractal Design XL case
-Coolgate 3x120mm rad at the very top of the case
-Coolgate 2x120mm rad at the very bottom of the case
-Swiftech MCP355 pump with Bitspower DDC top
-Swiftech XT cpu waterblock
-(x2)XSPC 6970 waterblocks
-Phobya resevoir

I know the basic flow of a normal 1 rad CPU loop(Res>Pump>Rad>CPU), but where should I put the pump in my loop? Can I put it at the bottom of the case? Does it have enough power to pump from the bottom up through the 3x120mm rad at the top of the case? The 2x120 radiator will be at the very bottom of the case.

With a 1 CPU / 2 GPU / 2 Rad loop, should it go Res>Pump>3x120 rad>cpu>GPUs>2x120 rad? Seems like a large loop for one pump. I also have an older MCP650, but didn't want to use it as it is loud and annoying.

Any suggestions are appreciated!

 

[EarthwormJim]

Your pump can pump water to a height of 20 feet. Don't worry about placement as far as performance goes.

Loop order really doesn't play a big role, the water is pretty much at equilibrium temperature everywhere. Set up your loop to use the least amount of tubing possible.

The one thing you do want to focus on besides tubing length, is placing your pump just after your reservoir. It makes filling much easier.

 

[Tsumi]

Your single 355 is most likely enough. If you can get the apogee xt v2, get it, it has much lower restriction than the original xt.

The only important thing is pump below reservoir, and immediately right after it. Anything else does not matter.

 

[sethmo]

Thanks guys, I believe this is how my loop will end up(Don't mind my awesome MSPaint skills)

There is enough room behind the mobo tray for 1/2" tubing, will just have to figure my cable management a bit differently if I route the tubing back there. Have to figure out where the fill will go, if the reservoir is small enough and there's enough room in my case, I can probably just use the top port in the reservoir to fill.

 

[Erasmus354]

Your pump can pump water to a height of 20 feet. Don't worry about placement as far as performance goes.

Loop order really doesn't play a big role, the water is pretty much at equilibrium temperature everywhere. Set up your loop to use the least amount of tubing possible.

The one thing you do want to focus on besides tubing length, is placing your pump just after your reservoir. It makes filling much easier.

I can't express how happy it makes me to come back into the Watercooling section after years of staying away from it and find someone with common sense knowledge making a correct recommendation! The amount of people who don't understand fluid dynamics making claims of "radiator before cpu to get the coldest water!" (admittedly technically true but practically unnecessary) or "slower flow so that the water has more time to cool down in the radiator!" were mind boggling.

Huzzah to you and a +1 on the recommendation.

 

[Thor]

I can't express how happy it makes me to come back into the Watercooling section after years of staying away from it and find someone with common sense knowledge making a correct recommendation! The amount of people who don't understand fluid dynamics making claims of "radiator before cpu to get the coldest water!" (admittedly technically true but practically unnecessary) or "slower flow so that the water has more time to cool down in the radiator!" were mind boggling.

Huzzah to you and a +1 on the recommendation.

however, both are correct (rad before cpu and slower flow in the rad for longer cool down). the water in my old 939 loop (with a 1.120 BIX) would have almost 5°c difference between hot nozzle and cold nozzle... (under full load after 2 hours of gaming... hell there was a 2+°c difference between my cpu and the video card in the same loop). so it dose (at least in my experience) matter, but it is probably more loop dependent, and the ones with bigger rads will have the lower difference in temps.. obviously. now.. that said, you pump will add heat to the loop, but it is not affected by the heat put off by the other parts so its output should be last in line.. again, the bigger the setup is, the less this will matter.

 

[EarthwormJim]

however, both are correct (rad before cpu and slower flow in the rad for longer cool down). the water in my old 939 loop (with a 1.120 BIX) would have almost 5°c difference between hot nozzle and cold nozzle... (under full load after 2 hours of gaming... hell there was a 2+°c difference between my cpu and the video card in the same loop). so it dose (at least in my experience) matter, but it is probably more loop dependent, and the ones with bigger rads will have the lower difference in temps.. obviously. now.. that said, you pump will add heat to the loop, but it is not affected by the heat put off by the other parts so its output should be last in line.. again, the bigger the setup is, the less this will matter.

You probably had very low flow rates. With high flow rates, the water is moving so fast, it only experiences a very very small change in temperature when going through a CPU block or radiator. The idea, is to have tons and tons of water molecules exchanging small amounts of heat at a very rapid rate. Not to have a small amount of molecules exchange large amounts of heat. You want all the water at equilibrium.

You do not want low flow anywhere, including the radiator. The idea that at low flow the water molecules spend more time in the radiator is flawed. At high flow, the water is able to cycle through the loop faster, so while it may get through the radiator twice as fast (arbitrary example), it'll go through it twice as often.

 

[Thor]

You probably had very low flow rates. With high flow rates, the water is moving so fast, it only experiences a very very small change in temperature when going through a CPU block or radiator. The idea, is to have tons and tons of water molecules exchanging small amounts of heat at a very rapid rate. Not to have a small amount of molecules exchange large amounts of heat. You want all the water at equilibrium.

You do not want low flow anywhere, including the radiator. The idea that at low flow the water molecules spend more time in the radiator is flawed. At high flow, the water is able to cycle through the loop faster, so while it may get through the radiator twice as fast (arbitrary example), it'll go through it twice as often.

if you call an ehiem 1048 and full DD blocks slow... (not by any means) the reason there was such a difference was because of the small rad that just barly kept up, and the high volume high pressure sunon fan i had to use. the system wasnt built for quiet. it wasnt built for speed ( as the board i had wouldnt OC for shit) it was built for stability. It folded 24/7 for nearly 5 years with only a week of down time in that 5 year period (i moved).