Scratch Build – Complete ⭐ Monolith - almost passive, compact gaming PC

Howdy y´all!

I have started a new project this week. And its going to be another scratch build. It does not have a name yet. Im always bad with naming things, but if you have any suggestions, let me know!

Sponsors

I would like to thank my Sponsors Fischer Elektronik, Impactics and MSI for the support and the trust im my work!




Fischer Elektronik gave me this beautifully made, gigantic chunk of aluminum, which i chose out of their vast variety of heatsinks, to perfectly fit my needs for the project. The support on their website helped my understand the whole concept of passiv cooling better than before. Thank you very much!




Impactics has PC cases, which offer silent passiv cooling and look stunningly beautiful. Whenever you want a silent HTPC, you should definitely consider Impactics! They gave me a bunch of heatpipes for my project. Thank you very much!

MSI provided a lovely GTX1080 graphics card and a Z270I Gaming Pro Carbon AC. Thank you very much MSI!















Concept:
After i finished my silent HTPC project im going to build a more powerful gaming machine, but still keep the noises levels to a minimum. Also its supposed to be as small as possible and good looking of course. At least the technical characteristics powerful, small, very quiet usually done go well together

I have to admit, its not going to be completely silent as my HTPC is, but im not sure about running a high-end gaming PC with no airflow what so ever, so there will be two 140mm fans, which should only be (quietly) operating at high load. They will be mounted in the top and suck hot air through the hardware compartment, but also through the heatsink to improve its performance.

Since im still in love with my HTPC, the design of this build is going to be pretty much the same, just a little more badass


Design:
Because of the more powerful internals, the cooling system is going to get a tiny little bit bigger, compared to my HTPC.
Thats why im using a 300x300x84mm, 8,5kg high performance heatsink from Fischer Elektronik.
The frame will be made of Alfer Aluminum tubes.


The mITX mainboard and graphic card will be mounted to the heatsink with a copper block in between the two parts. Additionaly a few heatpipes will be used to spread the heat evenly on that gigantic heatsink.


As i said, there will be two 140mm fans in the top, which should only be operating under heavy load.


And thats how is supposed to look like when its done. And the blue parts in here will be made out of acrylic, which will be lit up be RGB-LEDs.



Hardware
Im not completely sure what hardware i will be using for the build yet. Whenever i know, i will let you know.



Getting started:
i cut a bunch of scare tubing and put the frame together:




just for a size comparison

 

It's a great idea, and I like the case design, but I've been here myself, and I remember calculating that a heat sink twice that size would struggle to get rid of all the heat. It's the GPU that really adds the watts...

I would do some calculations first to make sure that sink can shift the TDP of your setup. Also would try to keep the heat pipes in as vertical an orientation as possible.

 

Awesome.
Building a frame for a heatsink like this, though. It IS the frame.

 

yes thats true.
basically the heatsink is the main structure and pretty much half of the whole case, which holds all the hardware. The frame just holds the aluminum panels and the fans.


i did a few calculations before i started. and im glad you asked, so you can check if im mistaken at any point

lets assume we have 250watts to get rid of just for the CPU and the GPU, for example 7700K + GTX1080, all the other parts like PSU, RAM, voltage regulations,... will be cooled by that airflow, not by the heatsink.
If you take a look at the datasheet of the heat sink im using (SK531), you will find that it performs at about 0,15K/W at natural convection.
Multiplying that by our assumed maximum wattage 250W x 0,15 K/W = 37,5K of delta between heatsink and air.
i also found this sheet (in german...) with a bunch of technical explanations.
On page 2 you will find a graph, that shows the effect of forced convection on the performance of a heatsink. According to this graph, at 1m/s airflow, you have about 66% of the thermal resistance, compared to natural convection. At 1,5m/s you will end up at about 50%.
That means:
250W x 0,15K/W x 0,66 = about 25K delta sink/air
250W x 0,15K/W x 0,50 = about 19K

The rest of the system is way more difficult to calculate. All i read was, that i cant be done, because it depends on too many factors like how you put the heat in the sink, how you transfer the heat to the sink.

but lets just add 10K for the coupling of the heat pipes to the sink and another 15K for the CPU- and GPU blocks, which should be plenty.
That means i end up at 50K delta CPU/GPU to air at 1m/s airflow. At lets be honest, about 70°C for both the CPU and GPU would be a great result.


you may have noticed that i calculated with an air velocity of 1,0 or 1,5m/s and i did that for a good reason. lets say you use the Eloop B14-2 (datasheet), which moves about 110m³/h at 900RPM and each of the two fans sucks air through a square of 15cm x 15cm, which is about the size of my build, you get the following calculations:

110m³/h / (0,15m x 0,15m) = 4888m/h x 1h/3600s = 1,35m/s

in reality i will have obstacles everywhere, which will restrict the airflow, but they will also narrow it down. so i dont know how fast the air will be, but 1m/s will the least possible velocity.



ok, it took me an eternity to write this, but this is what i thought of before i started this build. i know it is all based on many assumptions and in the end i just hope for the best

if i, in your oppinion, made a mistake, please tell me!

 

now i totally forgot about writing my progress...

i finished the frame, cut a few holes in it and tapped the same amount of threats in the heat sink.

 

This reminds me of this thing: Klick here

Also check the Linus Tech Review

 

Yeah, i saw that video of Linus while i was planning this whole thing and it actually confirmes many of my assumptions!

The system they used was a 5820k and a Titan X. So that adds about 30watts for the CPU, compared to a 7700K and about 80Watts compared to a GTX1080FE, which is about 40% more for the whole system.
They do have a little more than 3 times the heat sink size, compared to my build, but no fans at all. If i use two fans to improve the capability of the heat sink (as i calculated above), i should get about the same performance as the Calyos system.
And they had stunningly good temperatures!

edit:
i guess im mistaken. in that Linus video they seem to have used a GTX1080 as well.

 

todays progress: i milled a notch in both sides of that POM board, where the LEDs will be placed, drilled a few holes in it, to hold the two 140mm fans and drilled a few more holes in both the acrylic and the aluminum, so everything can be mounted to the frame.

 

today's news: I tried to get the front panel bend. it didnt work at all. i tried it like i did it with my HTPC, but it seems bending a 350mm long panel is harder than a 50mm one. who knew....

but, after that i started working on the top. i used a cheapo router to get the cylindrical cutouts done.



....and made a complete mess. POM everywhere!


but the result looks good!


then i decided to do the cutout into the aluminum and acrylic panels at the same time.


...which also worked really well!




and thats how it looks right now


i tried to illuminate the acrylic with a flashlight

 

Let me check...



A GTX 1080 is 180W and an i7700k is 91Watts, so you're looking at 271W. So your delta will be 40.65K. A bit tight without the fans, but of course the components would only reach max temp during heavy (gaming) load, not casual web surfing so you could have the fans spin up only under heavy load.

On the upside, the coupling between the sink, heat pipes and components should add no more than 10K. However you also have to factor in heat pipe thermal resistance and how many heat pipes you need to shift the heat from component to the heat sink (rough rule of thumb is one pipe per 15W, so you're looking at 6 pipes for the CPU and 12 for the GPU, but it depends also on how much of the total length of the pipe makes contact with the component end and how much with the heat sink).

With regards airflow, this web page calculator says you're getting 1.36m/s, so your calculations check out.

 

The plan is to use 6 heat pipes for each the CPU and GPU. I just dont have any room for more.
If the pipes dont cut it, i still have that pure copper block that sits in between the GPU and the heatsink to transfers heat directly.
We will see how things turn out, but im confident


I worked on the fan grill. I cut 7 strips out of 3mm acrylic, using a jigsaw. After that i drilled holes through all of them and grinded them down to get matching ones.
I also made another mess, but this time i cleaned up before my wife came home, so no spanking for me this time.







to give you an idea of how its going to look like:

 

There's a thought: how is the PSU cooled? You don't have any headroom left to dump its heat in the big sink. But these days most PSUs have pretty silent fans.

 

Hey man you may want to watch this.

It may be of some help

 

@nexxo: there are two options.
One is that i modify the PSU. Get rid of the internal fan and put a few holes in that side, where all the cable attach. There should be enough room. That way the fan, that sits right above the PSU will be able to suck air through it.
Option two is to leave the PSU as it is and cut an opening in the side panel. that way the internal fan of the PSU can suck air from the outside and exhaust towards the top fan.

my favorite is option one because i dont want any more moving parts than the two fans on top.

@Vault-Tec: i know that video. i saw it when i was planning and calculating my build.


today i put the side panels on.







i tried to illuminate the acrylic with a flash.

 

Option 1 should work fine as long as you accept that the fans will be always active, but be sure to take temperature measurements to be safe. Otherwise you can replace the heatsinks inside the PSU for beefier models (they always seem a bit wimpy to me).

 

You could go for optimal air flow and remove the PSU from the case completely. But this will make tinkering very dangerous.

I made a customized PSU (custom wiring harness and custom enclosure) for my very first mod. I would avoid modifications that are not easily implemented if you you ever have to switch power supplies, such as replacing heat sinks. I abandoned that mod when I need to replace the power supply.

 

Im not sure about an external PSU. I want to keep things as standard as possible. As you said, you have to invest a lot of effort everytime you change things.

My plan is to use a PSU which has a quiet fan mode, when in idle, like the Corsair SF450 and just replace the internal fan with the one above it. That way the PSU conrols the fan according to its own temperature and load and should turn it off when in idle.
The rear fan could be controlled by something like a T-Balancer MiniNG. It has two temperature sensors, which i could attach to the CPU and GPU block and have the fan run according to the measured temps.
That way everything should be quiet when idling and safe when i put load on the system.

There are several more options. One is that i attach both fans to the PSU and have both of them be controlled by the PSU
Another one is i attach one fan to graphics card and one to the mainboard.
Or i use the T-Balancer Big NG, which is in my watercooled system right now to monitor all three components (PSU, GPU, CPU) by sensors and have the fans run according to that.

When i have the system running i will have to do a lot of testing and see how the temperatures will be, but having the fans run all the time is definitely not an option

 

Love the layered top + grill.
Crazy cheapskate suggestion mode: I would cut the plexi fins so they sit flush with the aluminum layer in the top. I assume you will be cutting grooves in the POM to hold them in place?

 

Exactly. I hope to get that done tomorrow.

you mean like in that screenshot? (at the bottom is how i have it planned right now)



i thought about that and decided not to do it, because its a lot more work...
i would have to make different ones for each groove and since i already cut the acrylic strips i decided to take a look at it first and MAYBE ill make new ones if i dont like it.

yesterday i had an idea, because i found 10mm thick acrylic.
Instead of making the feet out of aluminum and have them anodized black like the rest of the panels, i might make them out of acrylic and have them lit up with RGB-LEDs.
What do you think?




also, since i already tried and failed at bending the front panel with a nice radius, does anyone have a suggestion on how i could bend that damn thing?

 

BOO!

Bend: A pipe 'anvil' with the right radius and a mallet? I'm not the best person for bending advice. My stuff comes out lumpy because I don't like to go slow.