Custom Loop Order (CPU & 3x GPU's)

[Cobra Khan]

Hello all,

Zardnok recommended that I post my question here so I hope you all can help.

I am going to be building my first computer ever (I go balls deep the first time haha) and have a question about my loop order.

First, here is what my system will look like:

CPU: Intel Core i7-4770K Devils Canyon Edition
Motherboard: Asus Maximus VI Hero ATX LGA1150 Motherboard
Memory: G.Skill Ares Series 16GB (2 x 8GB) DDR3-2400 Memory
Storage: PNY Optima 240GB 2.5" Solid State Drive
Storage: Western Digital Caviar Black 1TB 3.5" 7200RPM Internal Hard Drive
Power Supply: EVGA SuperNOVA 1300 G2 1300W 80+ Gold Certified Fully-Modular ATX Power Supply
GPU: 3x R9 290's
Optical Drive: Asus BW-12B1ST/BLK/G/AS Blu-Ray/DVD/CD Writer
Case: Rosewill BLACKHAWK-ULTRA Gaming Super Tower
Monitors: 3x Tempest X270OC
GPU/CPU Water Blocks & Complete Water Cooling system: ($750)

I have started to make get some idea's of how I want to loop the system.

As of now, I have it set as Resevoir> RAD> CPU> GPU's> RAD. My reasoning for doing this over Resevoir> CPU> RAD> GPU's> RAD was because I think it will just look "cleaner" in the case that way. From what I have read, loop order isn't nearly important as it would be in a car for example.

So I guess my question is, would it be advisable to run the loop as Resevoir> CPU> RAD> GPU's> RAD? I plan to put a "medium-high" overclock on the CPU and GPU's so performance>aesthetics

Resevoir> RAD> CPU> GPU's> RAD

Resevoir> CPU> RAD> GPU's> RAD

I found this, but not sure if it applies to a scenario with three GPU's and a CPU in the same loop:

 

[z1ggy]

In the long term, loop order does not matter, as long as your res is above your pump. Otherwise, do what is best to make plumbing easiest. Keep in mind fill and drain points.

 

[Tweakin]

In the long term, loop order does not matter, as long as your res is above your pump. Otherwise, do what is best to make plumbing easiest. Keep in mind fill and drain points.

As z1ggy stated, the delta between the order is minimal at best. You will make more impact on the system by the type of rad you choose and which fan you have.

The difference in your two plans may be 1c across any reference point. I do have one question, are you planning on running all three cards in parallel or series?

 

[Cobra Khan]

I do have one question, are you planning on running all three cards in parallel or series?

Ahh, and what an excellent question that is. To be honest, I have no clue because I never got around to checking out the different ways of doing so just yet.

Do you have a recommendation?

 

[guskline]

Cobra Khan: I'm hardly a water cooling expert but my sig below shows the system I have.

Keep in mind multiple high end gpus such as the R9 290 dump a ton of heat into the loop. You don't have specifics on your WC components but from your visual it appears that you are using a large 360 rad plus a large 240 rad. The biggest question you need to address with 3 GPUs, 1 cpu and 2 rads is the type of pump you are going to use. I like the D5 pumps. Since I have a XSPC RX360 internally plus a MO RA3-420 externally (Yes I know I'm overadded but it's my "toy") I went to a twin D5 XSPC dual bay reservoir pump system running the D5s in series. Incredible flow rate.

Hopefully BrightCandle will chime in with suggestions. He has helped me a great deal with WC info.

I suggest you visit this site to research flow rates etc in more detail;
http://martinsliquidlab.org/

 

[Cobra Khan]

Cobra Khan: I'm hardly a water cooling expert but my sig below shows the system I have.

Keep in mind multiple high end gpus such as the R9 290 dump a ton of heat into the loop. You don't have specifics on your WC components but from your visual it appears that you are using a large 360 rad plus a large 240 rad. The biggest question you need to address with 3 GPUs, 1 cpu and 2 rads is the type of pump you are going to use. I like the D5 pumps. Since I have a XSPC RX360 internally plus a MO RA3-420 externally (Yes I know I'm overadded but it's my "toy") I went to a twin D5 XSPC dual bay reservoir pump system running the D5s in series. Incredible flow rate.

Hopefully BrightCandle will chime in with suggestions. He has helped me a great deal with WC info.

I suggest you visit this site to research flow rates etc in more detail;
http://martinsliquidlab.org/

Haha you can cool a car with that radiator!

I bought an Alphacool Dual 5.25" Reservoir with single D5 port yesterday so I was thinking an MCP655 should just about do the trick.

 

[guskline]

Haha you can cool a car with that radiator!

I bought an Alphacool Dual 5.25" Reservoir with single D5 port yesterday so I was thinking an MCP655 should just about do the trick.

D5 is a great pump.

 

[BrightCandle]

You haven't said what your cooling intetions are so I will address the power/heat part of the equation. A triple card system is hostile to cool. The 290 is a 300W card, and it runs up against its TDP limit quite often. 3 of them even not overclocked is 900W, your CPU is another 150W. Plus the rest of the systems consumption and I while I think it just about fits inside your 1300W PSU you don't have much in the way of headroom for overclocking the GPUs. So be aware these cards consume vast amounts of power when you overclock them and you could be looking at nearly 1600W loads mostly from your GPUs.

Cooling 1050W is going to take either a lot of noise or a lot of space. Typically we say that the best thick 120mm radiator slot will cool 130W to 10C with an 800rpm fan. That is pretty quiet, its not silent but its nearly there and most people are pretty happy with 800rpm. You would thus need 8 fan slots. You can probably get about 200W out of a fan slot if you paid no attention to noise, maybe get somewhere around 5 fan slots but they would be running at more like 2000 rpm. I don't know if your case has the space for this amount of cooling, I don't know it I am just mentioning its hard to cool this amount of heat quietly.

This is also a long loop, its going to be quite slow flow and that will impact the temperatures. No normal pump can cope with 4 blocks like this without a big drop, a basic D5 isn't going to cut it. Typically what people do in your situation is they go two loops, make the GPU a warmer loop and put the CPU on its own loop. To do it all in one loop means you probably want to use a dual pump solution or at the very least one of the more powerful ultra Swiftech pumps. You need flow and you are asking a lot of a pump with 2-3 radiators and 4 blocks.

I wouldn't say this build is very sensible for a first timer actually, there are a lot of challenges and trade offs with this many GPUs.

 

[Cobra Khan]

You haven't said what your cooling intetions are

Well, the reason I went with 3x 290's was to power my three 2560x1440 120hz monitors with high settings (or get as close as possible). Because I didn't want an afterburner inside my case, I pretty much HAD to go with water cooling with this setup unless I want an extremely loud heater in my office. Because I am going water cooling, I may as well OC to and get as much performance out of my system as I can, safely.

So, I have no intention of benchmarking this thing to death to get that extra 1C cooler. I am simply doing this out of necessity because three air cooled 290's would be unbearable to me.

I would say I will only be gaming at the most one hour a day, so the GPU's won't be anywhere near full load 90% of the time I use it.

Not sure if that answers your question or not.

The 290 is a 300W card, and it runs up against its TDP limit quite often. 3 of them even not overclocked is 900W, your CPU is another 150W. Plus the rest of the systems consumption and I while I think it just about fits inside your 1300W PSU you don't have much in the way of headroom for overclocking the GPUs. So be aware these cards consume vast amounts of power when you overclock them and you could be looking at nearly 1600W loads mostly from your GPUs.

Good point. Other mentioned this as well in another thread. I will increase my PSU.

Cooling 1050W is going to take either a lot of noise or a lot of space. Typically we say that the best thick 120mm radiator slot will cool 130W to 10C with an 800rpm fan. That is pretty quiet, its not silent but its nearly there and most people are pretty happy with 800rpm. You would thus need 8 fan slots. You can probably get about 200W out of a fan slot if you paid no attention to noise, maybe get somewhere around 5 fan slots but they would be running at more like 2000 rpm. I don't know if your case has the space for this amount of cooling, I don't know it I am just mentioning its hard to cool this amount of heat quietly.

I have already bought eight Corsair SP120 High Performance fans (5 for RAD's, 3 for ventilation) which I found to be a good fit for my application.

As far as my case goes, I have a Rosewill BlackHawk Ultra. I could build two computers inside of it and still have room. Space is not an issue.

My case also comes with five 140mm fans as well as three 230mm fans, so I know I am set there.

This is also a long loop, its going to be quite slow flow and that will impact the temperatures. No normal pump can cope with 4 blocks like this without a big drop, a basic D5 isn't going to cut it. Typically what people do in your situation is they go two loops, make the GPU a warmer loop and put the CPU on its own loop. To do it all in one loop means you probably want to use a dual pump solution or at the very least one of the more powerful ultra Swiftech pumps. You need flow and you are asking a lot of a pump with 2-3 radiators and 4 blocks.

Hmm, this is a good point. I will have to do some more research and see if I can find a more suitable pump.

I wouldn't say this build is very sensible for a first timer actually, there are a lot of challenges and trade offs with this many GPUs.

I like a challenge

 

[Aikouka]

If we consider the "rule" that you should avoid excess piping, I would go RES -> CPU -> TOP RAD -> GPUx3 -> BOT RAD ... which is actually the same way mine was setup. The only negative aspect is that you get some rather short runs, which can be a bit of a pain.

I have already bought eight Corsair SP120 High Performance fans (5 for RAD's, 3 for ventilation) which I found to be a good fit for my application.I like a challenge

You may want something to adjust the speed of those fans, because SP120 High Performance editions are rather loud. Well, to be fair, I've heard a lot louder when it comes to fans, but if you're looking for a quiet system, you'll need to take that into account. Also, to note, in my opinion, even the Quiet Editions aren't that quiet. To me, you don't reach quiet status until you're around 15dB... 20dB tops.

 

[z1ggy]

OP, I would probably do the 3 GPU's on their own loop with two 480 rads, and then the CPU on it's own loop into a 360 rad. I say 360 rad because it gives you some headroom in case you want to water cool any other components like VRM, etc, although I think a 240 rad will be just fine for the CPU alone.

1)This makes your loop simpler (IMO)
2)Temps will be lower on the whole for your system
3) You can run the fans slower so it'll be quieter
4)You can get fancy and have 2 different res' and run multi colored tubing/coolant etc for added

Oh.. And crap for some reason I hought you had a 900D for a case. Can your case even fit 1200mm worth of rad space? B/c to dissipate that much power, that's about how much you'd need, even if you only run full load 1hr a day (480 + 480 + 240 ).

 

[z1ggy]

If we consider the "rule" that you should avoid excess piping, I would go RES -> CPU -> TOP RAD -> GPUx3 -> BOT RAD ... which is actually the same way mine was setup. The only negative aspect is that you get some rather short runs, which can be a bit of a pain.



You may want something to adjust the speed of those fans, because SP120 High Performance editions are rather loud. Well, to be fair, I've heard a lot louder when it comes to fans, but if you're looking for a quiet system, you'll need to take that into account. Also, to note, in my opinion, even the Quiet Editions aren't that quiet. To me, you don't reach quiet status until you're around 15dB... 20dB tops.

He can use the CPU header fan and OPT_FAN header (if he has one) on his mobo to control those SP120's.

 

[Cobra Khan]

You may want something to adjust the speed of those fans, because SP120 High Performance editions are rather loud. Well, to be fair, I've heard a lot louder when it comes to fans, but if you're looking for a quiet system, you'll need to take that into account. Also, to note, in my opinion, even the Quiet Editions aren't that quiet. To me, you don't reach quiet status until you're around 15dB... 20dB tops.

Yes I will be on watch for a used Temp/Fan control bay unit. I have about 3-4 months until I want this completed so I am going to be taking allot of time to get the right components (at good prices haha) and do the research so I am prepared when build time comes.

OP, I would probably do the 3 GPU's on their own loop with two 480 rads, and then the CPU on it's own loop into a 360 rad. I say 360 rad because it gives you some headroom in case you want to water cool any other components like VRM, etc, although I think a 240 rad will be just fine for the CPU alone.

1)This makes your loop simpler (IMO)
2)Temps will be lower on the whole for your system
3) You can run the fans slower so it'll be quieter
4)You can get fancy and have 2 different res' and run multi colored tubing/coolant etc for added

Oh.. And crap for some reason I hought you had a 900D for a case. Can your case even fit 1200mm worth of rad space? B/c to dissipate that much power, that's about how much you'd need, even if you only run full load 1hr a day (480 + 480 + 240 ).

Wow, that is allot of radiator. I am fine if the cards get to 65-75C. I was thinking about doing two 360's. Would that really not be adequate enough to keep the cards at that temperature?

 

[aigomorla]

I found this, but not sure if it applies to a scenario with three GPU's and a CPU in the same loop:

The holding potential of water is calculated while looking at 2 main variables if we ignore things like turbulence.
GPM -> Flow + Actual Heat Load.

thermodynamics states, as pure water (distilled) is moving 1.5gpm it can roughly handle 350W per 1C.

I dont know where u got that graph but he himself is breaking thermo with those heat numbers.
The delta at the 552W range is too small with the flow he has listed, hence he has broken thermo.

I am assuming he took TDP, and not actual heat numbers, as 600W heat source itself will increase the water temp more then 1.5-1.7C.

The rules of thermo states:
1. You must play the game.
2. You can not cheat and get something from nothing.
3. You can never quit.

So if something doesnt add up to thermo, it means its not physically possible.

Wow, that is allot of radiator. I am fine if the cards get to 65-75C. I was thinking about doing two 360's. Would that really not be adequate enough to keep the cards at that temperature?

honestly.. split your loop up.
Or keep your CPU first as you will form what is called a temperature gradient inside your loop due to the lack of flow.
As bright listed, you will be netting almost 1kw to your gpu as a potential heat source, which means u will probably net near 3C+ temp gradient.
This is accounting for the added restriction of the extra blocks where you wont reach a 1.5gpm, but more boarder on the .7gpm(+/-) with a single pump.

How does that translate? well, not very much... your gpu's will still be a lot cooler then air, you'll probably get 45-55C and not 65-75C,
However if u invested that much in your gpu end, a extra 150 or so, to get a new pump/rad shouldn't break your budget... It will lower your restriction, and increase your flow rate due to the lack of blocks, and allow water to be more efficient where u hit the sweet spot on flow at .8gpm -1.2gpm.


Also my system is probably near par in the heat load values you have.
I am running a TRI-SLI config, with a Hexcore, and well... i have 3 loops... spread out on 4 rads.
CPU -> PA360
GPU-> MCR320 x 2 (stacked with high static 38mm fans in the center)
Board -> PA160

But ziggy's advice is solid... if u don't want to invest in more radiators tho, id say keep your CPU on the 240, and your GPU's on the 360.

 

[Cobra Khan]

thermodynamics states, as pure water (distilled) is moving 1.5gpm it can roughly handle 350W per 1C.

I dont know where u got that graph but he himself is breaking thermo with those heat numbers.
The delta at the 552W range is too small with the flow he has listed, hence he has broken thermo.

I am assuming he took TDP, and not actual heat numbers, as 600W heat source itself will increase the water temp more then 1.5-1.7C.


The rules of thermo states:
1. You must play the game.
2. You can not cheat.
3. You can never quit.

So if something doesnt add up to thermo, it means its not physically possible.

Soooo.....what you're saying is.....more radiator!!!

I can fit a 480 at the top of the case and a 360 at the bottom. I could possibly fit a 480 on the bottom, but I am not positive if the PSU would allow me enough room.

 

[z1ggy]

Yes I will be on watch for a used Temp/Fan control bay unit. I have about 3-4 months until I want this completed so I am going to be taking allot of time to get the right components (at good prices haha) and do the research so I am prepared when build time comes.



Wow, that is allot of radiator. I am fine if the cards get to 65-75C. I was thinking about doing two 360's. Would that really not be adequate enough to keep the cards at that temperature?

It is a lot of rad, but as a loose rule of thumb, you generally want 120mm of rad space per every 100W or so of power/heat dissipated. Now this may change slightly if you have the fan config as a push pull, or if you use something like a Monsta (thicker than 60mm) rad.

I can't say for sure if two 360's will cut it. I want to say it will just barely make those temps, but I haven't seen too many set ups with three R9 290's.

Most of the setups I see generally have 1 or 2 cards. The 2 card set ups generally have a 240 and a 360 to cool the two GPU's and CPU, so I assume you could get safe temps with a third card and an additional 360.

I'll keep looking for you and get back to you. I'll assume you'd be ok with temps in the 70C range.

Edit: Seems like 2x360rads should be fine.

 

[aigomorla]

Soooo.....what you're saying is.....more radiator!!!

I can fit a 480 at the top of the case and a 360 at the bottom. I could possibly fit a 480 on the bottom, but I am not positive if the PSU would allow me enough room.

no im saying u will need more flow => more pumps, with more radiator.

because u will form a gradient without flow.

EDIT: it seems its a skinnelabs graph.
i talked to him on MSN, and he told me those values are numbers he pulled from a killawatt.
Assume nothing in the world is 100% inefficient, where it dumps all the wattage into heat... his graph makes sense... as the values listed are probably 70-80% of actual heat load values.

EDIT2: LOL skinnee gave me a new chart saying his old one wasnt precise.
This is the real chart which does make sense.

 

[Cobra Khan]

It is a lot of rad, but as a loose rule of thumb, you generally want 120mm of rad space per every 100W or so of power/heat dissipated. Now this may change slightly if you have the fan config as a push pull, or if you use something like a Monsta (thicker than 60mm) rad.

I can't say for sure if two 360's will cut it. I want to say it will just barely make those temps, but I haven't seen too many set ups with three R9 290's.

I guess I should have mentioned the widths I was planning on. I had originally planned on a 360/240 Monsta setup

Either way I need to figure out exactly how much space I will have in the case. I may as well utilize all of it.

Worst case scenario I can only fit a 480 and a 60mm 360

no im saying u will need more flow => more pumps, with more radiator.

because u will form a gradient without flow.

Gotcha. Now I just need to figure out if I can run another pump in succession in the same loop since my reservoir only has one port for a D5. If not, I will just sell it and buy dual cylindrical reservoirs and put them inside the case.

 

[z1ggy]

I guess I should have mentioned the widths I was planning on. I had originally planned on a 360/240 Monsta setup

Either way I need to figure out exactly how much space I will have in the case. I may as well utilize all of it.

Worst case scenario I can only fit a 480 and a 60mm 360



Gotcha. Now I just need to figure out if I can run another pump in succession in the same loop since my reservoir only has one port for a D5. If not, I will just sell it and buy dual cylindrical reservoirs and put them inside the case.

The thicker the rads though, the more air pressure you will need, keep that in mind. Luckily, those SP120s are one of the best static pressure fans around, although that comes at the price of loudness.

I'll keep checking about the rad space for your set up, but for now it seems like two 360's would be okay as long as you have good flow. You will have to carefully monitor your temps though under full load. I would run some diagnostics to make sure things are all good once you have the build in place.

Also, there's no way you're going to get the loop you want for $750. The blocks alone will cost about $500(3 gpu blocks & 1 cpu block). If you opt for compression fittings, that will run you an easy $100+. Now you have $150 for a res, pump(s) & tubing. Not happening my friend.

 

[aigomorla]

Gotcha. Now I just need to figure out if I can run another pump in succession in the same loop since my reservoir only has one port for a D5. If not, I will just sell it and buy dual cylindrical reservoirs and put them inside the case.

or you can get a dual D5 bay res and make it cleaner.. :biggrin:

 

[Cobra Khan]

or you can get a dual D5 bay res and make it cleaner.. :biggrin:

I could, but I kind of like the idea of two loops if I have to get another res anyways. It will come down to whatever I can get a deal on though. Both options work for me!

 

[Cobra Khan]

I just emailed Joe from Frozen CPU and he said I should be able to loop in another MCP655 in the same loop even though I only had a reservoir with one D5 inlet. So I can keep my Alpha Cool Dual Bay 5.25", which is cool because I got a really good deal and don't want to get another one!

Also, there's no way you're going to get the loop you want for $750. The blocks alone will cost about $500(3 gpu blocks & 1 cpu block). If you opt for compression fittings, that will run you an easy $100+. Now you have $150 for a res, pump(s) & tubing. Not happening my friend.

Yeah I think it will be $1k by the time I am done with it. Already got a deal on one of the GPU water blocks for $80. Shouldn't be too far off budget.

Once I figure out how to get this HDD cage out of my case I can take some measurements lol

 

[guskline]

I'm glad that aigomorla and Brightcandle have joined this discussion. I can tell you that my rad system RX360 + MO RA3-420 would give you the rad capacity. The BIG difference is that I coupled it with a Twin D5 XSPC Bay res. The two D5s running in series keeps the flow rate up. It's overkill for my single 3930k @ 4.6Ghz and single GTX 780 Classified OC'd. However, with your proposed setup, you'll definitely use that cooling capacity.

If you have not bought your PC case yet I would seriously look at the Phanteks Ethoo for @$240 or if you can swing it the Corsair 900D at @$320.

When you go to multi gpu setups with water cooling sufficient rad capacity and the space to place it become critical. I purchased a CM HAF 932 Adv and due to size constaints I had the RX 360 at the top internally and had an external rear mount of a EX360 until I purchased the MO RA3 420.

 

[guskline]

Here's a picture of my HAF 932 with the external MO RA3 420. I have a set of Koolance quick disconnects between the internal RX 360 and the MO RA3.

 

[Tweakin]

Ahh, and what an excellent question that is. To be honest, I have no clue because I never got around to checking out the different ways of doing so just yet.

Do you have a recommendation?

Considering the thermal wattage you need to remove from your system, I would go serial as the water pressure will be higher.