Hello everyone
in a level1techs video Wendell asked who and why would someone buy a RX7900 or RTX4090 to play in 1080p and to explain it in forums so here goes.
WHY 1080P :
I have a very special 10y old 27" 1080p TN monitor
an old 3d model where the lightboost hack works LightBoost HOWTO | Blur Busters
this gives me zero ghosting nor motion blur, not less…NONE
I can read the street names on this and they look as sharp as a still picture TestUFO: Photo
“working” black frame insertion has no competition, sadly it’s apparently very hard to make, as usual a hack worked better than what manufacturers do 
playing on anything else feels like going from 120fps to 30fps you can’t go back from this
oled is close but not quite the same, I’m placing my hopes into recently announced LG 27" 1440p oled monitor
the monitor flickering nonstop isn’t going to last forever one day it will break and then I’ll move to oled, no VA or IPS for me
THE BUILD :
this is the 25th iteration of my personal PC and has seen 6 different computers inside it
9900k z390
3960x trx40
5950x x570
12900k z690
13900k z790
it started as an all air cooled and ended in a triple rad custom loop with everything in-between 1,2,3 rads cpu,cpu+gpu, cpu+gpu+vrm waterblocks, trying various models and brands of fans the lot…
a lot of work and testing to reach this design so I can say with little doubt you cannot make better at this size
SYSTEM PARTS :
- Case : Lian Li o11 Dynamic XL
- Motherboard : MSI MAG Z790 TOMAHAWK WIFI DDR4
- Memory : 4x8Gbs Corsair Dominator DDR4-3600 18-19-19-39 2T
- Videocard : Inno3d iChill Frostbite RTX 4090
- Soundcard : Creative Sound Blaster ZxR
- Network card : Intel X550-T1 10Gbps
- Storage : 4x nvme + 6x ssd
COOLING :
- Pump : Hydro X Series XD5 RGB Pump/Reservoir Combo
- Radiators : 2x Corsair Hydro X Series XR7 360mm (55mm) + 1x Corsair Hydro X Series XR7 360mm (30mm)
- Cpu waterblock : EKWB EK-Quantum Velocity² D-RGB – 1700
- Gpu waterblock : alphacool Eisblock Aurora Acryl GPX-N RTX 4090 Reference mit Backplate
- Fans : Corsair QL rgb 120mm fans
- Fan Controller : 2x corsair commander core xt
COMPROMISES :
- rear fan should be an intake for optimal cooling, but it gets accelerated by the top ones and starts whining, also it’s already an imbalanced 6vs4 intake exhaust 1 more intake is too many
- QL fans ? rated worst static pressure ! good enough and they have the softest air sound of all brands, yes better than noctuas who whine hard when they start actually pushing air, QL make a woosh even at max speed and while not silent you can absolutely work all day in the same room with no earplugs
- RGB ? completely uneccessary but can be turned off with 1 key press
- Fan placement ? the big compromise, fans work better in push but for the rgb I have the bottom and vertical fans set in pull, sucking air through a rad isn’t good but worse it changes the way the air exists the fan, in pull mode air exits in a 45° crown shape with almost no flow in front of the fan unlike push mode creating a straight hairdryer like jet, if you don’t want rgb and want maximum cooling place fans in push
DDR4 ? :
ddr5 is beta testing, I hate it only 2 sticks work at acceptable speeds and even like that it’s very finicky only g.skill worked on z690 corsair didn’t boot and on x670e it’s the opposite corsair boots but g.skill doesn’t
I couldn’t make my very expensive msi meg ace x670e ddr5 work and so it’s on a shelf for now
I wasted days and money with ddr5 but gave up went ddr4 with a 3600 kit I had and don’t regret it one bit “it just works”
I feel sad for the many topics I see in level1techs and elsewhere I tried to warn people since beginning 2022 that ddr5 didn’t work and all I got for it was shadow-banning, don’t ever ask a tech youtuber why he talks about 4 dimms support but reviews with only 2 dimms while having 20 sticks behind him, they don’t like when their dishonesty is exposed
COOLING DESIGN :
this is not based on theory but reality
I tried all the combinations possible and I mean all…even inverting fans 1 by 1 on rads to see if chaotic airflow would somehow work
this gave me the best result, minus using the rear fan as intake which gives you better temps but make an annoying whining noise because the top-rear fans accelerate each other going above spec
the rear fans is mostly there to exhaust gpu backplate heat but on a watercooled 4090 even with no active backplate it’s quite tame, mildly warm air is all I feel
this can render process videos or whatever for 8hrs straight with barely an impact on your room temperature
that’s what the 3rd rad is for, when it comes to liquid cooling if your liquid temp goes above 45°C it’s a fail > 45°C liquid temp has a noticeable impact on room temperature you want to stay below
this config with the 13900k and 4090 both very good at idle as seen in below picture 8hrs of idling (network disconnected) is I dare say, cold !
air cooled and with older cpu and gpu I had no heating and was sweating in briefs at night in winter, now I’m cold, the room temp dropped at least 10°C which is good because my air cooled 3960x+1080ti running 100% cpu for 9hrs gave me 48°C/118°F room temp in summer, that’s what triggered the move to liquid cooling
I think that covers the build itself
the 13900k and 4090 both need a different message because I have a lot to talk about them, everything reviewers don’t tell you (sadly)
EDIT : when I said ultimate I meant ultimate compromise which might not be everyone’s definition of ultimate ><
- it’s not the ultimate cooling (use non rgb fans and set them all in push mode)
- it’s not the ultimate performance DDR4 is a limit factor for sure
but if you want performance & temperatures & noise levels & rgb it has all
I just demoed to a friend and his comment at max fan speed (1700ish) “wouldn’t bother me while working”
) I repasted it with thermal grizzly kryonaut which gave me the best temperatures I have ever seen on a gpu, I have no aircon my room is at 23-25°C I kept the overheating results for a reason which i will explain below
!
