H2Overkill: Extreme Cooling Without the Extreme Looks



H20verkill: Extreme Cooling without the Extreme Looks

I toyed around with the title for a few minutes, A lesson in frustration and A lesson in how to potentially ruin a computer for marginal performance gains just didn’t have the same ring to it.


Here is the finished project

Story Time

Sit down ladies and gentlemen, this will take a while.

Our story begins almost 2 years ago. I had just returned home from contracting in Afghanistan, and I had a whole bunch of money burning a hole in my pocket.

Build a PC,” I heard from a nasally voice somewhere deep down.
PCMasterRace,” it squealed, while incessantly tugging at my overflowing wallet.

“I do enjoy PC Gaming, and my 4 year old laptop is really showing its age when I play Skyrim,” I thought. “Maybe I should do some research on Computer Components tonight.”

Research… yeah.

If you’re like me, research usually ends in a shopping cart full of shit you don’t need. This was no different. I discovered The worst website to go to when you have some extra money PCPartPicker.com and away I went.

A few hours later, sweaty and out of breath, I cleared the haze from my eyes and beheld the horror in front of me. Not just a shopping cart, but order confirmations had filled my inbox.

“***Glorious!***” Shrieked the voice.

Oh god what have I done.

Within a few weeks I had everything, it wasn’t my first time building a PC, but this was definitely the most expensive and highest performing PC I had ever built. I assembled, setup my OS and installed Steam. I fired up a game and cranked the graphics settings to 11. It was beautiful, no doubt, but my god was it loud. 760’s in SLI sounded like a turbine engines. Case fans running at max speed were creating enough wind speed and turbulence to ground a Cessna.

Something had to change.

watercooled or gtfo

Damn it. Time for more research

I couldn’t justify the cost at the time, I mean I had just bought a bunch of stuff I didn’t need, and the wife was already pissed enough, so I decided to take it slow. Watercooling was uncharted territory for me. I mean, sure my hair was turning white, and I had a sudden interest in deep V-Neck T-Shirts, but I didn’t know anything putting water inside a computer. I knew I wanted maximum cooling ability, and I knew I didn’t want any flashing lights or uv reactive fluid. I wanted subtle performance.

I watched youtube videos, reviews, read countless articles, assembled parts lists, reassembled parts lists, drew mock builds, measured for radiator placement, watched fan reviews and noise tests, calculated how much cooling capacity I would need for a dozen different builds, etc etc…

Finally almost 2 years later, I had a good idea of what I was doing, and I was tired of having to wear hearing protection every time I pushed the power button. I logged onto another bad website to frequent when you have extra money Performance-PCs.com and assembled my shopping cart one last time.

About a week later I had all the parts I would need:

EK waterblocks for CPU, Motherboard, and GTX980ti

ST30 Alphacool Radiators (420, 280, 240, 140)

Alphacool D5 PWM Pump, Koolance Straight and 90* Fittings, Swiftech 8-way PWM Splitter

Alphacool 150ml Res with Pump Top, Silver Kill Coil

20ft Primochill Advanced LRT Tubing 3/8 - 1/2, Clear, 3 Noctua NF-F12

8 Noctua NF-A14

Benchmarking Before

Just out of curiosity, I ran some benchmarks to moniter temps, nothing serious.

CPU Stress Test: AIDA64 System Stability Test
GPU Stress Test: UNIGIN Heaven Maxed Settings

I ran them simultaneously for 10 mins


CPU @ 50
GPU @ 57

ROG RealBench

Temps were about the same
Score: 117867


Goodnight Sweet Prince

Glamor Shot, looks pretty enough

Cable Management

Lets take off the Dust Filters and the front fans

Oh my god

Case is empty, and Motherboard stripped (except RAM for some reason, Don’t ask questions.)

Motherboard Waterblocks

Motherboard and waterblocks

Chipset heatsink off, ready to clean, reapply thermal paste, and install waterblock

The Chipset Waterblock had this weird 5th standoff in the empty hole on the bottom, I had to remove it after a test fit, the standoff was sitting on a thing on the motherboard, preventing me from mounting it. Must be for a different board setup despite being labeled as Maximus VI Formula specific.

Top Stuff Heatsink removed and prepped for waterblock install

Waterblocks installed, no ROG Thermal Armor

CPU Waterblock

Glamor Shot

Reviews had said that the install was tricky, so I prepared for the worst. They were referring to removing the OEM Backplate picured above. 3 bolts. It gets Replaced with

And just like that…


Video Card Waterblock

So Fancy

Stock Cooler Removed, Thermal Paste applied to GPU

Thermal Pads for all the other Video Card stuff

Waterblock on!

I get to reuse my cool EVGA OEM Backplate right???

Wrong. Add to Shopping Cart.


So Pretty

I had to preinstall one fitting, because I knew there was going to be some clearance issues. I was pretty much just crossing my fingers that the 140mm Rad and Fan were going to fit above the I/O panel and not block the Motherboard fitting

Damn that’s tight. Looks like it should fit. We’ll see.

Radiators / Fans

That was the Hard Part, right? Radiators should just bolt up, right?

Silly RedBeerde. Nothing is that simple.

According to Corsair, the 750D can fit a 360/280 top, 280/240 front, 240 bottom, 120/140 rear.
4 radiators. No “either/or” qualifiers… Guess what. There is a lot of Either/Or

The 280 front and 240 bottom don’t play nice. In fact no front and bottom radiators play nice. The case is designed for the front radiator to be mounted low, almost touching the bottom, and the bottom radiator to be mounted forward, almost touching the front. Obviously one of them has to move. The front rad did have some mysterious unmarked mounting holes in a 280mm pattern that would raise the front radiator almost 40mm, flush with the 5.25 bay carriage. Unfortunately I needed about 5mm to account for the radiator core in order to line up with the holes.

Nothing a hammer can’t fix.

Problem solved, Almost.

Remember that 40mm gap I talked about? I needed 55. (30mm rad + 25mm Fan) No one makes 15mm fans or rads, so I improvised.

That was easy, wait… the case is sitting on the fans.

Solution: Lift Kit for the 750D

Velcro, 3/4" steel spacers, and furniture feet. I’ll think of something better later. I Might just fiberglass over the lift kit. make it look real fancy.

I started getting tired, and took less photos than I should. Long story short, the 420mm Rad fit up top, but only with the fittings towards the front. So much for my hopes of having short runs. The 140mm rear radiator and fan did fit, but only by a hair.

So here:

280mm Front in Push/Pull with 240mm Bottom in Push

140mm Rear in Pull, fittings up

420mm Top in Pull, fittings forward.

Pump / Reservoir

Ooohhh… Aahhhhh.

Assembly was simple, mounting was interesting. I found two holes that look like they may work. They are close to the SSD mounting bays though, but that shouldn’t be an issue…

Wow that was a pain

Everything installed, ready for tubing.


Relatively straight forward, Nothing fancy, just soft tubing. Only one spot that concerned me was going from the top motherboard thing to the CPU block

A little ugly, but it’ll do.

Oh much better. Now I get what a 10’ mod is.

Lets follow the flow.

Pump --> 280 --> 240 –

–> Chipset --> GTX980Ti –

–> CPU --> Top Motherboard Stuff Waterblock --> 140 –

Not Pictured
–> 420 --> Resevoir

Fill and Leak Test

Filling System

I went to fill and bleed the system only to find that my PWM D5 pump could barely produce a trickle. At its current rate it would take 12 hours just to fill the radiators. Without a motherboard to plug into, the D5 had no PWM signal and defaulted to its minimum RPM. There had to be a better way.

PWM Looks for a 5v signal at 100%.
MOLEX provides 5v on the wire opposite red.

Oh wow.

Leak Testing. I’m going to let it run overnight. The drips on the towel under the reservoir must just be from me spilling a little while I filled…

May as well do some Cable Management while I wait.

12(ish) Hours Later…

After breakfast I decided to check in on the leak test. That spot where I thought I spilled? No. That was a leak. Right out of the Pump Housing. I went to check the tightness of the bolts, and found on stripped out. Perfect.

Good for me, I had a tap laying around for 10-24 which is one size up from OEM threading, I just needed to go get a socket head cap screw in order to fit the bolt in the recessed surface.

While I was doing all this, I noticed an O-Ring for one of the fittings sitting on the bench. Oh no.

I began the arduous task of removing each fitting to find the on who was missing an oring. While none of the fittings were leaking at the moment, introduce heat and time to the system and one day I will wake up to a very expensive paperweight.

Found it. Chipset input 90* Fitting.


Remember way back when we mounted the reservoir? Turns out it does block the SSD cage mounting holes.


Well I am not about to drain, relocate, refill, and releak test again.

Problem Solved.

What a mess.

Less of a mess

Mess Solved. (Don’t look on the other side)

Ready for Benchmarks!





Damn it. Nothing, Just a pulsing Republic of Gamers LED mocking my failure.

In my rage I didn’t take any pictures of the problem, but after doing some research it seems that the most likely culprit was the NGFF / WIFI Adapter on the ROG Z87 Boards. I did move it around a bunch while I was plugging stuff in, so I assumed I unseated it or something.

Of course its not as simple as just unplugging it. Its located in just about the worst possible spot.

I had to remove the rear 140mm radiator, Video Card, and unseat the motherboard itself in order to shift it enough to unscrew the retaining screw on the bottom of the motherboard. If it wasn’t ruined before, it sure is now.

Fortunately, the soft tubing gave me enough play to do all of this without draining and disconnecting the lines. If I would have had to drain and refill again, I probably would have just thrown my PC straight into the trash.

With everything remounted and hooked up, its time to try this again!





Such relief.

Watercooled Benchmarks

Same tests, looking for Temps

CPU @ 41
GPU @ 33

ROG RealBench

Temps were cooler than AIDA due to the on/off cyclic nature of the RealBench
Score: 124873

CPU lost 9*
GPU lost 24*
ROG RealBench Gained 7000 points. whatever that means.

@ Idle

CPU and GPU sit around 27-30* vs 37(CPU) - 45(GPU) on air.

The real benefit is sound.
All those benchmarks had the fan set to 13% / 170 RPM. Pump set at 60%. Effectively Silent.

I tried to increase my overclocks, to no avail.

CPU: 4.6 @1.27v via BIOS (I can get 4.8 stable @1.37, but that voltage is just too high for the mediocre gains)
GPU: 1650mhz @ 100% power via EVGA Precision X

So was it worth it? Spend all that money and deal with all that frustration for slightly better performance, and significantly cooler components?

Yes. Absolutely. Plus I love the looks. I have never been into the flashy crap that comes with “gaming” oriented hardware, and in fact I dislike the color scheme of the motherboard itself, but it is subtle enough that I am OK with. The black and clear colors from the watercooling setup are subdued enough that they don’t stand out in a room, but give off a clean and powerful look when you are looking at the tower. It was exactly what I was looking for.

So there you have it. That’s how you fit 4 radiators in a 750D while only partly destroying the case. Good enough for me.

Next on the list: New power supply.

Dog were witness to all this.


New to Water Cooling

Wow. This is way better than my build log.


Great write up!


Nice way to come up with solutions man. Awesome build!


dude epic thread!


I don’t think you have enough radiators :smile:. Awesome build!!! I really would like to include my GPU into my loop but I’m not sure I’m willing to take mine apart. lol. I also ran into the same exact issue with the resevoir in that location on my case (I have the same one). I only have one SSD so it was no issue for me.


I agree this was a great read.

My question is: Were the 760s SLI really that loud? I’m currently running 970s SLI, have a fan in every slot possible on my case (6 total I believe?) plus my cables are just dangling, not run thru the back all neat like yours.

Noise level is not an issue at all for me and heat hasn’t been a big deal either.


I was waiting for your comment on the sound card :wink:


Noise levels are such a personal thing. What may be fine for one person, is unacceptable for another. The 760’s were using the EVGA ACX 1.0 cooler, and were positioned right about head level on my desk. When they were pushing hard, the fans were audible throughout my home. Even with headphones on I could hear them.

I did get used to it, and going from 760’s in SLI to the single 970, then 980ti, made a large difference in sound output, but was still more than I wanted.

Having it nearly silent now, even when pushing cpu and gpu hard, has really spoiled me.

The fan noise on air was tolerable, and the GPU’s were the main offender. Now the noise output is ideal. The loudest component is the power supply, which is something that had been completely drowned out before from the gpu fans.


I think by now everyone knows my stance on the sound card. Hey, maybe that’s why my system runs so great! Offload the sound :hankey:

Maybe I need to record the sound level in my room. Perhaps after 30 years of computering I’ve become oblivious to the noise. Or maybe my hearing is shot due to operating heavy machinery in my younger days.


I’m only sad I have but one :heart: to give to this post!