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dual nexxos gpx coolers restrict flow, help wanted.

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Droidhackzor

New Member
Joined
Jan 14, 2016
i currently have my system set up on a single loop with cpu and two nexxos gpx ati coolers, now, i have been aware of the restriction in these blocks but something seems to be causing even more of a restriction or posibly a back-flow pressure problem. here is the current setup.
20160114_075531.jpg
1x xspc led ring cpu cooler
1x ek 420 rad for cpu
1x mcp655-b pump (~317gph)
2x nexxos gpx ati coolers with crossfire cooling bridge( high restriction point)[ whitepaper says 4.5psi back-flow pressure is posible and could be problem]
1x xspc 240 rad for video cards

aparently, the mcp655-b has a max pressure of 50psi (1200 lph) i would have thought that one of the pumps should be enough but when the liquid gets to the cards, it only trickles down to the cards and then opens back up to fill the tubing afterward therefore the flow is hindered somewhere. but i can't seem to find the culpret.
the liquid travels fine to the cpu and 420 rad but slows to a trickle afterward then after the video cards, as long as there is enough fluid it fills the second rad without issue and back to the res.

so the question becomes, would i need to add a second pump in series to make up for the 9psi back-flow pressure? or just take the video card off the main loop and do a second loop, i realize that doing a second loop is preffered in most cases to keep the temps seperate and having better deltas but from my understanding, you technically might loose a degree or so having one loop but your total efficiency with one loop is better.
any ideas?
thanks in advance

Update: so adding a second mcp655-b in series seems to have solved the problem for now. Now I just have to watch the temperatures.
 
Last edited:

GTXJackBauer

Water Cooling Senior Member, #TEAMH20HNO
Joined
May 22, 2011
Location
USA
Don't think going with two pumps is going to solve the problem. I think you have a bigger issue at hand.

Is that the "XSPC" CPU WB? Never seen one like that before. You sure it isn't a knock off?

Have you cleaned your gear prior to installation to make sure all the manufacturing tid bits are gone and not clogging up your WB's micro lanes?

Why use colored fluid? Hope you know the consequences on using it and the long maintenance involved to maintain it from clogging or staining.

I personally would have went with another company for your GPU blocks. I'm not a big fan of DeepCool since they seem to have a pattern of being a Chinese knockoff company as we've seen already at CES (Two years in a row now?).

Anyways, I would do a complete tear down and check your water cooling components for debris.
 

GTXJackBauer

Water Cooling Senior Member, #TEAMH20HNO
Joined
May 22, 2011
Location
USA
Looks like you have the pump inlet/outlet backwards? Inlet goes to the middle of the pump. Inlet should ALWAYS be fed from the res.

+1 Good eye Con! Totally missed that. Hope the pump is ok as it could be running dry that whole time.
 
OP
D

Droidhackzor

New Member
Joined
Jan 14, 2016
My bad, you are corect caddi, it is an enzo luna, and no conundrum, the pump has the pump top mod, so the conection is correct. In from the technical side of the pump mod, out from the technical front of the pump mod. Res>pump>cpu>420rad>gpu's>240rad>res
 

caddi daddi

Godzilla to ant hills
Joined
Jan 10, 2012
I don't remember any tops that reversed the inputs and outputs.
please link us to the tops home page so we can read the installation manual.
this is to dangerous to be guessing at.
 

Conumdrum

Member
Joined
Sep 15, 2007
Location
Small town Emlenton, PA
Agreed caddi, it's wrong. I looked at many tops and have seen and used some. It's wrong.

What exact top is it? Post a link...........

And he symptoms are exactly what we have see before when they get it backwards. We ain't new at this.

NO centrifugal pump or fan has an outlet from the middle, and ALL watercooling PC pumps are centrifugal since I have been watercooling.
 
OP
D

Droidhackzor

New Member
Joined
Jan 14, 2016
the pump mod is the bitspower pump top mod v2, the connection was correct, though it doesn't matter now, i got the dual pump mod top extreme from them and the flow is now back to normal with the added pressure. but just for the rest of the thread, here is the original pump top mod v2 page.
http://www.frozencpu.com/products/i..._V2_-_Acetal_BP-D5TOPP2EX-BK.html?id=hm7AFveE

and here is my actual pump top showing the ports that i used (they don't have fittings in them since i had to use them with the new pump and mod top.
20160115_093811.jpg

also, for the sake of information, i did drain the loop prior to taking that first picture.
 
OP
D

Droidhackzor

New Member
Joined
Jan 14, 2016
also, here is the completed build after i added the new dual pump top mod extreme and second pump, all is good so far with temps ranging from 19C - 29C at idle and 35C - 45C under load. 20160114_115448.jpg 20160114_115347.jpg
 

Waza

Member
Joined
Jan 21, 2014
Location
Finland
I use 8+ year old stock D5 vario that pushes 3 rads, cpu and two inline full cover GPU blocks fine.
You must have a blockage somewhere or the pump was not working properly. Maybe that top was was faulty.
 
OP
D

Droidhackzor

New Member
Joined
Jan 14, 2016
It's entirely possible that the pump top was faulty though I never had a problem until I got the alphacool NexXxoS GPX ATI R9 270X m08 coolers witch, acording to white papers has nearly the highest restricted flow of any gpu cooler a whopping 4.5psi back-flow pressure per card. So my guess is that it wasn't the pump top, it was the 9psi total back-flow pressure and the one D5 pump couldn't force that pressure alone. Your ekwb blocks have a minimum of 1gph anyway, my nexxxos gpx has half of that (at least on paper).
 

Conumdrum

Member
Joined
Sep 15, 2007
Location
Small town Emlenton, PA
the pump mod is the bitspower pump top mod v2, the connection was correct, though it doesn't matter now, i got the dual pump mod top extreme from them and the flow is now back to normal with the added pressure. but just for the rest of the thread, here is the original pump top mod v2 page.
http://www.frozencpu.com/products/i..._V2_-_Acetal_BP-D5TOPP2EX-BK.html?id=hm7AFveE



and here is my actual pump top showing the ports that i used (they don't have fittings in them since i had to use them with the new pump and mod top.
View attachment 173461

also, for the sake of information, i did drain the loop prior to taking that first picture.

Ahh, okay, it's not the middle out you used, it was the other out. Couldn't tell in the first picture. I retract my reality and use your reality.

Looks good, nice bends.
 

GTXJackBauer

Water Cooling Senior Member, #TEAMH20HNO
Joined
May 22, 2011
Location
USA
My apologies OP for mixing up the GPUs with another phony company. Alpha cool is well respected in the H20 community. I really like their nexxos rads.

Having a old CPU and those GPU blocks, I could see why your loop is so restrictive. I bet a MCP35x would have chewed right through because of their head pressure. Crazy knowing I've seen more complex builds with a single D5. Its almost like showing how time and innovation has triumphed in the water cooling industry. Pretty amazing.

Nice case btw. Lots of room. :thup:
 

caddi daddi

Godzilla to ant hills
Joined
Jan 10, 2012
what coolant is that? is it uv?
the twistys in the res, what color are they, I can't see yellow, red or green ( though I am part of a study where they inject my eyes with some kind of chilled monkey sperm to try to cure it).
 

caddi daddi

Godzilla to ant hills
Joined
Jan 10, 2012
well, that's what they are doing to me!!!! REALLY.

I like the twistys in the res, looks neat. and it looks like uv coolant.