00RaZoR11

It's logical to use it for Intel these days but not so much AMD. Not worth it if you are using it on the IHS opposed to a delid. 

90C at stock on a 9900k is completely normal. It is a cpu that runs VERY hot.

this has been an ongoing issue with the Laing DDC models. lack of airflow to cool the PCB and windings.
 
this has been a short remedy:

 
and even as far as to use a small fan:

 
ek has even identified the issue and packaged an elite series:

Did you check Eisbaer  or Eisbaer LT? 

Regarding the tubes, you can replace them with whatever tubes you want, including hard tubing.

If you want low noise, then AIO is not for you.

But if you are adamant on AIO, then get Alphacool Eisbaer 240 LT. It uses better pump than most of other AIOs, so you can get good cooling performance even with 7v adapter, which brings the pump noise to lower level

aesthetics
 
Normal pluming hardware doesnt fit the aesthetic of most builds.
 
They look perfectly fine in a 'steampunk' theme however.

well, usually we don't use that stuff because it looks kinda shitty. also, the hoses available for fittings like that are generally just not great looking either.
 
the pro's of using actual watercooling gear are these among others:
-you don't risk losing your warranty when a block fails and leaks on the electronics. usually warranty for watercooling hardware reads that you need to use watercooling hardware.
-fittings made for the application are bound to be more optimized. usually with bigger holes for more waterflow (usually, not always)
-if you want to use hardline tubing, those industrial fittings are not going to work.
 

I wouldn't bother doing a push pull setup, especially with those expensive fans for such a minor improvement or any improvement in temps/noise.

as far as i know there's very little price difference between cheap large and small radiators.
By "fast" I meant 2000 rpm or higher. 

Use the arrows on the fans. make the air blow into the case while having the fans on the front of the rad.

Nope.  You got it.  The warm air isn’t all that warm though so pull works adequately, generally.  Part of it is modern CPUs just don’t make all that much heat compared to earlier ones.

Wait so you bought the h115i cooler, instead of new ryxen processor. Man like wtf. Your ryzen 5 2600 is fine with hyper 212 evo.
 
But Yeah, where do you have your case fans? use the bottom and the rear for exhaust, and the top and front for getting air in.

That’s certainly commitment.  You put holes in your house.  The issue is temp variability and condensation inside the house.  A cold enough coolant is going to cause condensation on the tubes  and “furniture” maybe?  This will put water in your computer.

Check your dew point:
https://www.calculator.net/dew-point-calculator.html?airtemperature=40&airtemperatureunit=celsius&humidity=40&dewpoint=&dewpointunit=fahrenheit&x=100&y=25
Monitor internal PC temp, and humdity.

“Roof radiator”. You running a custom loop and ran your radiator outside your house?

In push-pull ? Definitely, especially if this is gaming build, it's not going to draw a lot of power on the CPU.
And i'd like to make some suggestions for other parts :
- This AIO is cool and all but there's EVGA CLC 360 for 70$ cheaper, it's no worse.
- Same for the motherboard, there's Gigabyte Z390 Pro WiFi, very capable VRM too. Or at most, Gigabyte Aorus Ultra\Master or ASRock Taichi.
- You don't need 32GB RAM for gaming PC but it's okay if it's for video editing too. Altrough this particular kit is ... a little bit overpriced, get some 18\19CL kit, it'll be more than enough, it doesn't worth spending 350$ more for ~2% performance increase.
- Same for SSD, there's a lot of cheap and fast SSDs out there, like Team MP34, Inland Premium, Sabrent Rocket, ADATA SX8200 Pro, Corsair MP510 etc. And since you're spending several thousand dollars for a gaming PC, get 2TB SSD right away.
- This GPU SKU is a bit overpriced too, get EVGA XC or ASUS Strix for 300$ cheaper.
- Case is fine but you can get non-i version cheaper, the only difference are that worthless smart fan-controller thingy which isn't very smart at all.
- Get better PSU, Corsair RMx, Bitfenix Whisper\Formula Gold or Enermax Revolution D.F (which is practically the same PSU as Bitfenix Formula Gold), you don't need more than 650W for this build too.
- Come on, you ain't gonna see the difference between 144FPS and 240FPS, get some good IPS 1440p 144Hz display instead for cheaper.
- You don't need Windows 10 Pro for home usage, the only difference is that it can run in enterprise environment.
 
Minus thousand dollars for nothing. And since it looks like this is purely gaming PC (because of TN panel) you can actually get it even cheaper by getting 16GB RAM, opting for AMD platform and getting RTX2080 Super GPU instead.
 
PCPartPicker Part List
CPU: Intel Core i9-9900K 3.6 GHz 8-Core Processor  ($471.99 @ Amazon)
CPU Cooler: EVGA CLC 360 74.82 CFM Liquid CPU Cooler  ($99.99 @ Newegg)
Motherboard: Gigabyte Z390 AORUS PRO WIFI ATX LGA1151 Motherboard  ($159.99 @ Newegg)
Memory: G.Skill Trident Z Neo 32 GB (2 x 16 GB) DDR4-3600 Memory  ($159.99 @ Newegg)
Storage: Mushkin PILOT 2 TB M.2-2280 NVME Solid State Drive  ($223.99 @ Amazon)
Video Card: Asus GeForce RTX 2080 Ti 11 GB ROG Strix Gaming OC Video Card  ($1214.99 @ Newegg)
Case: NZXT H700 ATX Mid Tower Case  ($136.98 @ Newegg)
Power Supply: Enermax Revolution D.F. 650 W 80+ Gold Certified Fully Modular ATX Power Supply  ($79.98 @ Amazon)
Operating System: Microsoft Windows 10 Home OEM 64-bit  ($96.99 @ Amazon)
Monitor: LG 27GL83A-B 27.0" 2560x1440 144 Hz Monitor  ($379.99 @ Amazon)
Total: $3024.88
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2019-12-02 14:18 EST-0500

it's not good for your PSU. Every time you flick the switch after some time turned off, it will recharge its capacitors with a large burst current when you turn on your computer. Victims include:
 

Huh,  yeah,  RAM is apparently finicky with these CPUs,  so are motherboards,  and I'm getting very strong indications chipsets aren't ready either. 
 
But since AMD is the underdog, everybody loves them anyways! 
 
Well I don't,  ever since they got rid of ATi and their mobile GPUs (which was a huge mistake) they've never been the same. 

apparently it was just the ram.. It's very strange to me how even standard ddr4 settings didn't work with the old dimms, but the ripjaws work at xmp (3200 16-18-18). Even the POST is faster now.

Oh ok, sorry I didn't mean to come of as rude or anything, I was just a bit perplexed why you'd try OC the CPU, but that makes sense I guess... 
 
Have you tried another GPU? 
 
Because honestly I don't know if you're aware but the 5700xt is prone to crashing issues in many games,  it's all over the internet,  thousands of reports / complaints about this issue. 
 
Is what you're experiencing anything remotely similar like this (for example)? 
https://forum.worldofwarships.com/topic/203421-rx-5700-xtendless-crashing-support-says-known-bug/
 
 
In any case I'd recommend trying out another GPU to make sure that isn't the issue. 
 
Edit:  oops,  I just saw you did! 
 Well then this is a really curious case then.  Most likely motherboard / RAM issue, which also seems to happen a lot more often than it should with Ryzen 3000 platforms. 

you don't need pricy as heck samsung b-die, just buy any ram with decent speed (about 2800 or higher) that is on your motherboards QVL for Ryzen 2000

Here is a link https://www.asrock.com/MB/AMD/Fatal1ty B450 Gaming K4/index.asp#MemoryPR

Sort by ram speed, skip to about 3000 speed if price is a concern and start seeing what is available for a good price in your region.   Besides stability issues Ryzen 2000 runs like dog-poop if ram speed is too low, you want atleast 2800 speed.  but like others have said ram compatability isn't too hot with Ryzen 2000 either, so sticking to motherboard manufacturers QVL is crucial

Also i can't comment on Ryzen 2000 in regards to this next thing, but i'd be surprised if it was different to 3000 in this regard, but i can comment for sure that both Forza Horizon 4 and Battlefield 5 can run just fine with 8gb of Ram total (2x 4gb) sticks as i did this for over a month up until recently upgrading.   With steam/origin etc, and discord open, running a game i never saw more then about 6.5gb usage maximum, i do take care to turn off extra windows 10 backround processes, and have chrome etc set to shut down backround apps when i close it (you should do this with any browser, regardless of if you have 8,16,32gb etc or ram)


point being 16gb is nice for peace of mind, but in 99% of games, even very new ones, 8gb is more then sufficient if you don't have tonnes of stuff using ram (and likely cpu a tiny bit as well) in backround, so if you are on budget and can only get 2x4gb for 8gb total right now don't feel bad, definitely atleast run ram in duel channel tho (2x sticks in correct slots)

Samsung B-die is great, yes(Hynix is fine too B-die is more for overclocking and manually setting timings and such). This kit from Teamgroup is B-die, plus 3200mhz C16 for less than $60 if you're on a budget. If not going for Trident Z wouldn't be a bad idea, however a tad more expensive.
https://www.newegg.com/team-16gb-288-pin-ddr4-sdram/p/N82E16820331354?Item=N82E16820331354&nm_mc=AFC-RAN-COM&cm_mmc=AFC-RAN-COM&utm_medium=affiliates&utm_source=afc-PCPartPicker&AFFID=2558510&AFFNAME=PCPartPicker&ACRID=1&ASID=https%3a%2f%2fpcpartpicker.com%2fproduct%2fz3VD4D%2fteam-t-force-vulcan-z-16-gb-2-x-8-gb-ddr4-3200-memory-tlzgd416g3200hc16cdc01&ranMID=44583&ranEAID=2558510&ranSiteID=8BacdVP0GFs-ogYCDBS5M2ZgGn1deyZ8IQ

I can always recommend the Corsair Vengeance Kits. 
Got 2x 8GB 3000Mhz CL16 running at 3133 Mhz CL14  - Hynix modules btw. 

PS: Paired with a Ryzen 5 2600 @ 4.1 Ghz