Help on 900D GPU loop

coalminer071

New member
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So this is my current loop run. Its pretty fugly as it is, its my first watercooling build and with acrylic tubing.
The Run goes from Rez>(upsidedown)pump>flowmeter> top of GPU, bot gpu to bottom port of quad UT60, top port of quad to Bottom of dual UT60, and then the top of the Ut60 to a dual ST30 on the front, and then back to the rez.
temps are under 40 on heaven with ambient temps of low 20s. Recently i got a crack on the acrylic pipe which made me think theres too much restriction and therefore the pump is increasing the pressure even more. Please give me some advice on how to rework the runs. Thanks.
PS. Its going to be put into parallel when i get back:)

Edit: xspc razor 780
 
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What tubing are you using? I shouldnt think the tube would crack from the pump. I have MCP 35x which is a pretty strong one and no issues with my tubing. But high restriction wouldnt cause a crack really high restriction would just mean poor flow.

Why didnt you feed the GPUs from the bottom and outlet from the top though?
 
What tubing are you using? I shouldnt think the tube would crack from the pump. I have MCP 35x which is a pretty strong one and no issues with my tubing. But high restriction wouldnt cause a crack really high restriction would just mean poor flow.

Why didnt you feed the GPUs from the bottom and outlet from the top though?
primochill rigid acrylic. its 3/8 by 1/2. it could be from a stress bend. im pretty sure i do have poor flow considering i have 3 gpu blocks with 3 rads. If u can suggest any way i may change the loop runs, that would be perfect.
 
What fluid are you using?

(also, please don't bump threads, be patient, someone will respond, double posting is against the forums rules).
 
I would still run the loop from the flow meter into your bottom GPU first and out of the top. That would eliminate your U bend in the tube and also the 90degree fitting you have.

Considering you have done a decent job with the bending this helps with flow rather than slapping in a 90degree fitting.

http://martinsliquidlab.org/

This page will let you calculate the PSI required for your loop. Check it out and then calculate the components etc and compare it to your pump PSI rating.

At first glance though I don't see that much restriction in the loop. I am curious why you use a flow meter though. Personally I find them a distraction from the beauty of a well planned water loop.
 
Feser One uvs

The Glycol alcohol in it, might be causing your acrylic to fracture. I've got non uv feser and it hasn't caused any issues in mine, not sure if there is more in the UV stuff?



With regards pressure.. i very, very much doubt that a single pump (as it looks?) will cause enough pressure to make your acrylic fracture. I have 2 in series and it's fine. If there is *any* air in the loop at all (at top of res for example) that will compress much, much easier than anything else in the loop and will take any differences in pressure. I very much doubt that's a problem
 
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The hose wont have cracked because of the pressure.

Also parallel isnt what Id advise. The biggest issue with your loop is the hose from the GPU's down IMHO but that still wouldnt make me want to run anything but a series loop.

Ive been using a twin card system with a single loop for ages - Id much rather my rig be tidy
 
I would still run the loop from the flow meter into your bottom GPU first and out of the top. That would eliminate your U bend in the tube and also the 90degree fitting you have.

Considering you have done a decent job with the bending this helps with flow rather than slapping in a 90degree fitting.

http://martinsliquidlab.org/

This page will let you calculate the PSI required for your loop. Check it out and then calculate the components etc and compare it to your pump PSI rating.

At first glance though I don't see that much restriction in the loop. I am curious why you use a flow meter though. Personally I find them a distraction from the beauty of a well planned water loop.

About the psi calculation there isn't a resistance spec for the GPU blocks
 
The hose wont have cracked because of the pressure.

Also parallel isnt what Id advise. The biggest issue with your loop is the hose from the GPU's down IMHO but that still wouldnt make me want to run anything but a series loop.

Ive been using a twin card system with a single loop for ages - Id much rather my rig be tidy

What are the downsides of running a parallel loop?

------------------

The Glycol alcohol in it, might be causing your acrylic to fracture. I've got non uv feser and it hasn't caused any issues in mine, not sure if there is more in the UV stuff?



With regards pressure.. i very, very much doubt that a single pump (as it looks?) will cause enough pressure to make your acrylic fracture. I have 2 in series and it's fine. If there is *any* air in the loop at all (at top of res for example) that will compress much, much easier than anything else in the loop and will take any differences in pressure. I very much doubt that's a problem

I'll ask feser about the alcohol. It is a single pump loop
 
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What are the downsides of running a parallel loop?

There aren't any, they are pretty much the same, they just offer more outflow in some/most cases due to GPU blocks being restrictive in some cases (not all)

It all depends entirely on what is tidiest for your loop, in your case, serial looks like it will be best because you can go in from the bottom, and come out the top and go direct to either the CPU or Motherboard block. (or vice versa)

You typically go for parallel when you need to go in one side, go through all the cards, and come out the same end, so for example if you did
CPU > GPU 1, GPU 2, GPU 3 (in parallel) and then came back out the top and into the motherboard block. It would make for a tidy loop but your in-out would then only be at the top.

It totally depends on your radiator/pump layout more than anything else, as it's about keeping it neat :)


I'll ask feser about the alcohol. It is a single pump loop

Yeah man pressure won't be a thing, It might just be worth re-doing the bend in whatever piece has got the crack in it.

Could you take a half decent high-res picture of the crack? I'm interested in seeing it tbh.

This is crude, but i'd try this kind of layout personally (if possible, obviously depends on radiator orientation possibilities)

mdQti0I.jpg
 
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gpu blocks arent really something that adds a lot of resistance the ones i have seen dont have rediculous channels to force the water through like cpu blocks do.
i would try to avoid long vertical runs though. but if your pump has enough maximum head and your res is filled up pretty high even that shouldnt be an isue because the maximum head would be the equivalent of maximum head + fluid level in the res..

if you really think you have issues with resistance you could go with two pumps with one being used as a return pump pushing fluid back in to the res and the other being more conventional being fed directly from the res. but you would not turn the return pump on untill after you had fully primed your loop so fluid was already returning to the res without the second pump on. and you had gotten rid of the air in the system.

i had a set up like that. and honestly i didnt see any real benifit. also the more pumps you have or the higher the wattage of the pump. you also tend to transfer kinetic energy from the impeller to the water as heat. so you can end up with higher temps.

id imagine the actuall crack would have come from something totally diferent though. a seal would have gone before a pipe cracked if it was due to pressure.

edit

was editing a pic but an above post is close enough to what i was drawing so i wont bother
 
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i would try to avoid long vertical runs though. but if your pump has enough maximum head and your res is filled up pretty high even that shouldnt be an isue because the maximum head would be the equivalent of maximum head + fluid level in the res..

A D5's max head is about 13 feet dude..

I have a very similar loop to this one, minus one graphics card and it was flowing fine with a single pump on during filling/bleeding, the second is directly after the first which feeds straight from the res, flow/pressure/head isn't an issue here.

Where is the crack? on a bend or on a straight? can you mark it somehow, need to see it really.
 
A D5's max head is about 13 feet dude..

I have a very similar loop to this one, minus one graphics card and it was flowing fine with a single pump on during filling/bleeding, the second is directly after the first which feeds straight from the res, flow/pressure/head isn't an issue here.

Where is the crack? on a bend or on a straight? can you mark it somehow, need to see it really.

i disposed of the acrylic. it was the one that connected from the top of Quad to bottom of dual in the bottom area of the 900d. It was somewhat longer the first time i did a straight bend so halfway i did another 45 degree angle bend. it cracked in later portions of the pipe. btw how did you draw the red lines?
 
i disposed of the acrylic. it was the one that connected from the top of Quad to bottom of dual in the bottom area of the 900d. It was somewhat longer the first time i did a straight bend so halfway i did another 45 degree angle bend. it cracked in later portions of the pipe. btw how did you draw the red lines?

You can do it in the majestic Paint.
 
I wasn't saying GPU blocks offer restriction. What i was referring to is that the OP was concerned he might be restricted.

http://martinsliquidlab.org/pump-planning-guide/

The table mid way down on this page allows you to calculate roughly what you are using in your loop and comparable to what your pump can do.

GPU blocks vary between 0.1psi and 2psi. Most being around 0.3 which is nothing really.

But anyway...

The basic layout sub has "painted" is how I would run the loop. I always like to have my fluid being pumped "upwards into blocks"

ti0i.jpg


Excuse the crudeness and poor quality pic. I run two loops. And no there is no advantage or improvement over single. I just wanted to try something out since i had parts over from last build.
 
i disposed of the acrylic. it was the one that connected from the top of Quad to bottom of dual in the bottom area of the 900d. It was somewhat longer the first time i did a straight bend so halfway i did another 45 degree angle bend. it cracked in later portions of the pipe. btw how did you draw the red lines?

You can do it in the majestic Paint.

10 second job in Photoshop :) some vector lines, then i decided it needed arrows so used the brush tool :P

I wasn't saying GPU blocks offer restriction. What i was referring to is that the OP was concerned he might be restricted.

http://martinsliquidlab.org/pump-planning-guide/

The table mid way down on this page allows you to calculate roughly what you are using in your loop and comparable to what your pump can do.

GPU blocks vary between 0.1psi and 2psi. Most being around 0.3 which is nothing really.

But anyway...

The basic layout sub has "painted" is how I would run the loop. I always like to have my fluid being pumped "upwards into blocks"

ti0i.jpg


Excuse the crudeness and poor quality pic. I run two loops. And no there is no advantage or improvement over single. I just wanted to try something out since i had parts over from last build.

Regardless a D5 will have no issues with the setup he has tbh and it certainly won't crack the acrylic.

I'm more of a gravity follower usually, top down, but i have to admit, my current loop pushes up, i've found it makes for easier bleeding, and since the res is so utterly massive. I didn't actually have a whole lot of choice lol

It's all about neatness these days :)
 
thanks for all the comment guys. However tom did point out how hes not in favor of parallel runs. why is that? does anyone know?
 
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