Pump for 2x7990, 2 radiators and a CPU block

ZachCampbell4065 · Mar 28, 2015

Hi guys

Wondering if I could get any tips on cooling a i7-4790k and Crossfired 7990s. The Specs of the computer are:

Processor: i7-4790k
GPU: 2x7990
RAM: Dominator Platinum 2133MHz 16GB
Case: Corsair 760t
PSU: AX1200i
Motherboard: MSI Gaming 5
SSD: Crucial 500GB

So far for the cooling I have these parts thought out:

CPU Waterblock: Swiftech Apogee XL
GPU Waterblock: 2x XSPC Razor 7990
Radiator: 360mm (30mm) + 240mm (60mm)
Fittings: Lots of XSPC Compression Fittings (3/8")
Tubing: Primoflex Advanced LRT Red 3/8x5/8
Biocide: Silver killcoil
Pump/res: D5 Photon 170 pump/res combo

Would the pump be enough to handle all that resistance? And is it enough radiator?

Many thanks

JackNaylorPE · Mar 28, 2015

One post per toipic please

http://www.tomshardware.com/answers/id-2588578/pump-2x7990-radiators-cpu-block.html

Personally, I'd use a Swiftech 35x2 with heat sink and fan

OK here's the deal ....

Each card draws 389 watts ... add 10% for overclocking and you at say 430 each

So 135 watts for CPU + 2 x 430 for GPUs + 40 watts for the dual pump = 1035 watts

You will need at least 60% of that to be handles by the rads or 621 watts.

Using Alphacool rads and data collected from martinsliquidlab
http://www.overclock.net/t/1457426/radiator-size-estimator

Note that anything over 850 rpm is audible .... 1400 rpm starts to get annoying...

-30mm 360 will give you 150 watts at 1000 rpm
-30mm 360 will give you 181 watts at 1250 rpm
-30mm 360 will give you 199 watts at 1400 rpm
-30mm 360 will give you 242 watts at 1800 rpm
-30mm 360 will give you 281 watts at 2200 rpm

-60mm 240 will give you 101 watts at 1000 rpm
-60mm 240 will give you 125 watts at 1250 rpm
-60mm 240 will give you 140 watts at 1400 rpm
-60mm 240 will give you 179 watts at 1800 rpm
-60mm 240 will give you 217 watts at 2200 rpm

So... at 1400 rpm, you will have 339 watts of cooling or about 54% of the radiator you would want for a Delta T target of 10C. At airport noise levels of 2200 rpm, you'd be at 498 or 80%. If you go to push / pull on the rads .... you can get that up to about 20% higher

Do you need Delta T of 10C.... no you don't.... this is just the generally targeted design point for water cooling in a system of this magnitude.

At 1250 rpm you'd be at about 20C, 16.9 in push pull
At 1400 rpm you'd be at about 18C, 13.3 in push pull
At 1800 rpm you'd be at about 15C, 12.3 in push pull
At 2200 rpm you'd be at about 13C, 10.4 in push pull

Here's what I would do.

Enthoo Primo Case
http://www.newegg.com/Product/Product.aspx?Item=N82E16811854002

One XT45-420 on top w/ (6) Phanteks 140mm Fans in push pull
One Monsta-480 on bottom w/ (8) Phanteks 120mm Fans in push pull

That would give you 302 watts on top and 318 on bottom at 1250 rpm. for a total of 620 watts.

ZachCampbell4065 · Mar 28, 2015

I clicked the link but it 404s. The MCP35x2 isn't cheap! Also not readily available in the UK which is sad.

See, the interesting thing is that I am currently cooling a 4670k and a 7990 on 480mm of rad space, the card never goes about 50 degrees. According to the internet I needed 360mm alone just for the GPU.

As much as all of that radiator looks good, that much radiator and that much case is just a bit too expensive for me.

JackNaylorPE · Mar 28, 2015

No it isn't but when a single pump dies.... do you wanna wait 3 weeks or more where you are for a replacement to arrive.

Baccata is listed as UK distributor tho they are actually in france
http://www.swiftech.com/internationalresellers.aspx
http://www.bacata.net/index.php?p=produits&pid=6420

Other comments

CPU Waterblock: Swiftech Apogee XL - nice block but teh EK Supremacy Evo is the top CPU water block ATM

GPU Waterblock: 2x XSPC Razor 7990 - Again, EK rules here ...XSPC generally has very good GPU temps but VRM / VRAm temps are so so

Radiator: 360mm (30mm) + 240mm (60mm) - addressed above

Pump/res: D5 Photon 170 pump/res combo - I'd uggest a PWM version pretapped for G-1/4 fittings such as the one here ... and s separate reservoir such as the EK res 250.... thermal mass comes in handy unde rheavy but barying loads and stops the fans from chasing their tails so to speak as water temp changes.
http://www.frozencpu.com/products/18222/ex-pmp-231/Swiftech_MCP655-PWM-DRIVE_12v_Water_Pump_-_PWM_Enabled_w_G14_Thread_Ports_Perfectly_Tapped.html?tl=g30c107s1802

1LiquidPC · Mar 28, 2015

One MCP35X should be fine. When I was doing leak testing w/ my latest build, I only had 1 pump hooked up. I have the MCP35X2 as was mentioned earlier in thread(also recommend though expensive for a couple reasons). Anyways, I had plenty of coolant flow going through my reservoir as I was working out air pockets/testing ect. My loop is as follows RES-PUMPS-240-360-VRM-360-CPU-970-970-back to RES. I was using a D5 w/ my old setup as well, and no complaints there either, I'd recommend either pump. Also, are you going for temps or low noise as your primary goal? I'm asking I'd recommend as many rads as you can afford/fit in your case if your looking for both. Another example was my old setup, I had my OC'd 3930K, VRM/PCH blocks, and an HD 6990(Dual GPU) cooled with a D5 Pump and a single 480 Rad. My temps were good, but my choice of 38MM Fans were loud. I wanted much lower noise w/ my new setup.

ZachCampbell4065 · Mar 28, 2015

I already have an Apogee XL and am very happy with its performance.

What about the EK-XRES 140 D5 PWM?

JackNaylorPE · Mar 28, 2015

1. The question is can you afford to be without your system for a lengthy period of time while waiting for a warranty replacement. When the manufacturer is out of your country and your supply is limited, it could take 6 - 8 weeks or more to get a replacement.

2. The other issue is the one noted by martin is that 2 pumps at 50% PWM are a helluva lot quieter than 1 pump at 100%.
https://martinsliquidlab.wordpress.com/2012/01/29/swiftech-mcp35x2-pump/7/

If none of these bother you, then you can certainly get by with a single pump.... though I would make sure that you run your loop so that the GPUs are fed in parallel rather than serial.

ZachCampbell4065 · Mar 28, 2015

Well you could say that about anything, if my CPU breaks I have to wait a long time to get it replaced, doesn't mean I have 2 of those!

Won't running it in parallel reduce pressure?

JackNaylorPE · Mar 28, 2015

Well you could say that about anything, if my CPU breaks I have to wait a long time to get it replaced, doesn't mean I have 2 of those!

No you most certainly can not say that about anything when transactions occur across borders... .. if ya caught what OP said about the pump ?

The MCP35x2 isn't cheap! Also not readily available in the UK which is sad.

For the Swiftech 35X2, who has no warranty support in Europe, he would have to submit a claim to Swiftech, get permission to ship it, mail it, ... it would arrive in NY, and sit in customs for a few days, then be shipped to California where it would wait in the que to be examined, then if deemed a warranty failure, it would be shipped back to NY and wait for a boat, it would then arrive in customs where it will sit for a few days and then be mailed back to him.

Won't running it in parallel reduce pressure?

Yes, that's one of the reasons why it is done.... backpressure is a bad thing as it reduces flow rates and forces the pump to put more of its own heat into the loop as its working harder.

With 3 cards parallel might be a bit light but with 4 cards serial / parallel works great. The feed splits to cool cards 1 and 2 and then, 2 runs into 3 and 1 runs into 4 before coming back to the single feed.

The other is so you don't have the coolant from the 1st card getting 200 - 300 watts dumped in and then asking it to cool the 2nd. This way the cards have same temp.

Using 6 temp sensors, I have monitored the change on Delta T across the cards and with a decent water block .... anything above 0.50 gpm doesn't change Delta T. I can run about 2.25 gpm but under PWM control, it runs from about 1.0 at idle up to about 1.6 under heavy stress testing. I have tried pushing it up from 0.8 per card to 1.125 per card and it doesn't change card or water temps.

ZachCampbell4065 · Mar 28, 2015

I'm currently looking at the Phantek Enthoo Primo, supports 2 480mm radiators. Any advise on what radiators are good and if I should go 30, 45 or 60mm?

JackNaylorPE · Mar 28, 2015

Yeah ... see the end of 2nd post

Laid it all out for ya

I have twin 780s so don't have near the heat load of your 4 GPUs

But here's the Enthoo Primo with an XT45-420 and an UT60-280. You can see the drain in lower right .... fill and bleed ports are up on top.

One of these days I will do the cables.

ZachCampbell4065 · Mar 28, 2015

Apart from removing the HDD cages, which isn't a problem, is any modding needed for the bottom 480mm rad?

JackNaylorPE · Mar 28, 2015

You just remove the lower 3....and if ya want a drain... ya gotta figure out a way out somewhere

ZachCampbell4065 · Mar 28, 2015

Where have you got your fill port?

JackNaylorPE · Mar 28, 2015

Top rear of the 420

ZachCampbell4065 · Apr 2, 2015

Two questions about your case!

1) What is the maximum length that can fit with the reservoir bracket in place?
2) How much head room is there underneath the stealth PSU area?

JackNaylorPE · Apr 2, 2015

1. All (most of the relevant) of the dimensions can be found here in post No. 1000:

http://www.overclock.net/t/1418637/official-case-phanteks-club-enthoo-primo-enthoo-luxe-enthoo-pro-lovers-owners/990

You have room for cards up to about 10.6-10.7 inches.

2. The PSU is bottom mounted; sits on rubber pads on the case floor.... It's about 7" tall. The Seasonic X-1250 clears by about 3/4 of an inch.

ZachCampbell4065 · Apr 2, 2015

Just wondering if I can fit the MCP35x and accompanying reservoir in the stealth area, or if I should get a shorter graphics card and use the res mount

JackNaylorPE · Apr 2, 2015

I took out the lower HD cage and put the 35x2 under there. It also fits in the 5.25" bay area

ZachCampbell4065 · Apr 2, 2015

This is my plan so far http://i.imgur.com/hysLGrH.jpg (sorry about the terrible paint job, best I could do!). Forgetting tubing, what improvements could be made?

JackNaylorPE · Apr 2, 2015

1. You could paint the fan grilles, slot covers, SSD mounts, screws holding in logo and thumb screws ... add LED light strip to spare connector.... use like carbon fiber vinyl thing to wrap the SLI cable.

I put the fans as push (between the grilles and rads).

ZachCampbell4065 · Apr 2, 2015

Going to be replacing the Logo plate with a custom machined one, I'll leave painting for a while yet, LED strip is going either top or bottom or both, and getting 2x290x instead, so no need for a cable!
Would this plan work - http://i.imgur.com/obma8P9.jpg imagine the fans and stuff are swapped around but the rads and stuff are pretty much the same

JackNaylorPE · Apr 2, 2015

The 290x's are by far the better performer comopared tot he 295x2 ...

But twin 970s even more so at 1080p and 1440p (take the 290x at 4k)

For this build the new Acer IPS Predator (1440p IPS, 144Hz w/ G-Sync) would be killer. It's the new "best gaming monitor" at this point surpassing the Swift.

ZachCampbell4065 · Apr 2, 2015

My main issue with the 970, though its power draw and performance are impressive, is its price compared to how cheap you can pick up a 290/290x these days.
I'm definitely looking for a 144Hz monitor though, I have a 21:9 monitor for movies and multitasking but would like a high response time monitor for gaming. I'm not really looking to spend £700 on a monitor though

JackNaylorPE · Apr 2, 2015

Where are the prices different ? .... I mean for ones you actually wanna buy.

On newegg ...

Same Brand
MSI Gaming 4 GB 970 x 2 = $320 x 2 = $640 *
MSI 290x Gaming 4 GB x 2 = 400 x 2 = $800

Lowest Cost
Zotac 970 4GB x 2 = $620*
Sappire Tri-X OC 4 GB = $320 x 2 = $640**

* Comes with 2 $60 game coupons
** right now $10 coupon code

In UK ....

MSI 970 is £275.98
Sapphie Trix 290x is £287.15

I expect that the Predator will be around £579.99 same as the Asus Swift

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