Building of Aircooled dual 4090 Founders Editions System !

Own requirements :

• Highest possible amount of VRAM on GTX for V-Ray GPU in Maya (Windows 10)
• “Cheap” as possible without turning to Threadripper, Workstation MoBo, Quadro and watercooling
• Cool system during summer (30 degrees Celcius)
• Near silent if possible
• Lowest possible wattage/euro without losing too much rendering-times

The "old" system :

• Case : Be Quiet! Dark Pro 700 Midi Tower (https://www.megekko.nl/product/0/17...rs.net&utm_source=tweakers.net&utm_medium=cpc)
• PSU : Corsair RM850x (https://tweakers.net/pricewatch/463794/corsair-rm850x-zwart.html)
• Motherboard : Asus Prime X570-Pro (https://tweakers.net/pricewatch/1403126/asus-prime-x570-pro.html)
• CPU : AMD Ryzen 9 5900x (https://tweakers.net/pricewatch/1618232/amd-ryzen-9-5900x-boxed.html)
• Memory : Corsair Vengeance LPX 64Gb DDR4 3200Mhz (4x 16Gb)
• Cooling : 6x Be Quiet! Silent Wings 3 (https://www.megekko.nl/product/0/97...rs.net&utm_source=tweakers.net&utm_medium=cpc)
• GPU 1: Asus 1080Ti 11Gb
• GPU 2: Asus 1060 3Gb Blower

Intermediate Upgrades : Goal is to use 2x 3090 FE in December 2022

• Case : Fractal Design Meshify 2 XL
  • It must have 9 slots in the back
  • It has a large mesh in front = maximum airflow (Be Quiet! Dark Pro 900 does not have it)
• PSU : Corsair AX1600i
  • The final system has a maximum output of +/- 915W (with undervolt and underpowered settings for both CPU and GPU’s), but I also use the system for DCS non-VR (https://www.digitalcombatsimulator.com/en/). There might be spikes higher than 1000W so I just wanted to play safe… forever.
  • It has native support for Type-4 cables
• Cooling : 4x Be Quiet! Silent Wings 4 Pro (https://www.alternate.be/html/product/1855081?utm_source=Tweakers&utm_medium=cpc&utm_campaign=Tweakers_Case fan&utm_term=TL9V4G). Replacement for the Silent Wings 3 because they can be manually set to different and much higher speeds. I plan to increase the speeds on warm days and take the extra noise for granted.
• GPU 1 : nVidia 3090 Founders Edition
• GPU 2: nVidia 3090 Founders Edition
  • there’s a lot to tell about these …. Short version : they run too hot and too costly, period.
  • In order to give the first GPU breathing-room, the second GPU must be used in the lowest PCIe-16x slot. The first PCIe-16x will run at 16x and the second one will run at 4x. HeadsUp : as long as the scene fits in the VRAM of each GPU, the PCIe-4x will NOT bottleneck.
  • Modifications to the motherboard had to be done in order to give the second gpu space to fit in :
    • Bending some pins on the front-panel connector. It’s easily done using the provided extender for those same pins nad bending them one by one. In my case, only the Power On/Off, Reset-buttons and HDD-led were needed.
    • I used a 90 degree-adapter for the frontal USB3-connectors (https://www.amazon.de/dp/B08R7HPDL2/ref=pe_27091401_487027711_TE_SCE_dp_1). Be sure to buy the correct angle as there are 2 possibilities.
  • Bad thermal pads and fan-configuration caused the memory junction-temperature to rise well above its thermal limits, causing it to throttle down = 106 degrees ! Even though the hardware probably won’t break, nobody wants 106 degree air blowing in a case. It will cause premature failure on the longterm and that’s bad marketing for a 2000 euro’s GPU.
  • Second 3090 FE will blow hot air into the first 3090 FE = more bad news.
• Solutions:
  
  • Buy the right tool to disassemble the GPU (Fix it! https://www.alternate.be/iFixit/Mako-64-Bit-Driver-Kit-bitset/html/product/1436291)
  • Replace thermal pads
    .
  • Just be sure to buy the right thickness and type (Gelid Solutions GP-Extreme 1.5mm) (https://www.amazon.de/dp/B09GPKV34S/ref=pe_27091401_487027711_TE_SCE_dp_1) and use the template with a very sharp cutting knife
  • The temperatures dropped about 15-25 degrees. Using undervolt
    and underpower (MSI Afterburner -> Powersetting 70%), the maximum memory junction I saw were about 75 degrees ! Cool enough.

Final System preparation :

• Replaced both 3090 FE with 4090 FE : they are LITERALLY about twice as fast and they run a lot cooler (numbers will follow). I consider the 4090FE the new true new king without compromises (it would be the number one buy for non-corporates if it had NVLink, 2 Slot thickness, blower-style…. And 40Gb VRAM) what the 1080Ti was in the days and about the best upgrade possible in the history of GPU-upgrades for (pro)consumers. It’s THAT good !!
• The 4090 Founders Edition is a 3.5 Slot-GPU and that leaves about 7mm clearance between the PSU-shroud for the lower GPU. It might be enough of the frontal fans can push air deep and strong enough for the 4090 to pull them in. But I didn’t take that route :
• I placed the PSU outside the case. In order to do that, I had to lasercut holes in the sidepanel, exactly behind the existing holes in the case :
  • For once in my life, I was lucky…. Lasercutting in metal is not done by everyone. I contacted 10+ people/firms in Belgium and the Netherlands for that. Online services only accept their own materials, not custom like the sidepanel. They all responded, but nobody gave a green light. Someone was willing to drill holes and carve them out. Could have worked, but probably not as clean as laser.
  • … on the opposite side of my house, there’s a metal firm. Someone I went to school with and it’s mindboggling : he has a huge industrial laser !!! So, 1 month later after initially sending emails to everybody, I got the holes done in 12 seconds at the cost of 5 euro’s moral support, 30 meters away from my door ! All I needed was a AI (Adobe Illustrator-2-DWG/DXF)-file and my sidepanel. I have the last seconds of the cutting on video, because I wasn’t prepared.
• I ordered extension-cables for the PWM-fans (https://www.amazon.de/dp/B07FMZJ17B/ref=pe_27091401_487027711_TE_SCE_dp_1?language=en_GB)
• The PSU is standing quite good on a custom made metal table and with some cable-management doesn’t look too bad. The PSU is whisper-quiet. To be honest, it’s not a shame showing that PSU.
• Replaced the GPU-powercords with Corsair equivalent for cleaner layout (https://www.alternate.be/Corsair/60...-4-PSU-Power-Cable-kabel/html/product/1871728) . It has 600W rating, since each Type-4 cable can handle 300W (the default cables that come with the GPU can handle 150W/each).
• I placed a custom aluminium plate on top of the case to avoid air being sucked out before it reaches the memory and CPU.
• Raised the case with 1 cm to increase the inflow-capacity on the bottom.

Final System specs :

• Case : Fractal Design Meshify 2 XL (with 3 extra holes)
• Motherboard : Asus Prime X570-Pro
• CPU : AMD 9 5900x (12-cores/24 threads) @ 4.9Ghz
• Memory : Corsair Vengeance LPX DDR4 4x 16Gb (64Gb)@3600Mhz stable
• PSU : Corsair AX1600i digital
• Fans:
  • upper front 2x Be Quiet! Silent Wings 4 Pro @ medium-speed intake
  • lower front 2x Be Quiet! Silent Wings 4 Pro @ high-speed intake
  • 2x Be Quiet! Silent Wings 2 on top over CPU pushing out
  • 2x Be Quiet! Silent Wings 3 on bottom intake under second 4090 FE
  • 1x default Fractal Design in rear pushing out
  • the PSU-opening on the rear has been blocked out.
• Storage:
  • Samsung 970 Pro 1Tb
  • Samsung 980 Pro 1Tb
  • Samsung EVO 850 250Gb
  • Samsung EVO 850 250Gb
  • Western Digital 2Tb HDD
• GPU 1 : nVidia 4090 Founders Edition in PCIE-16 slot 1 (16x mechanical)
• GPU 2 : nVidia 4090 Founders Edition in PCIE-16 slot 3 (4x mechanical)
• 90 degree USB3-connector adapter
• 4090 Cables : Corsair 600W PCIe 5.0 12VHPWR Type-4 PSU Power Cable
• 3D Connexion SpaceMouse Pro Wireless (https://www.amazon.com.be/dp/B07PJ6...e=380333&creativeASIN=B07PJ6SV6C&linkCode=asn)
• Loupedeck CT (https://www.thomann.de/be/loupedeck_ct.htm)
• Logitech M570 wireless mouse
• Corsair K55 RGB keyboard
• Wacom Intuos 4 L
• MSI Afterburner : Powerlimit 75%

Results for V-Ray GPU RT in Maya 202x (same external hospital-scene WIP since forever @ 915 Watt system total. I no longer have the 3090’s FE to measure with) :

• 3090 x16 : 83 seconds @ 74 GPU/79 mem
• 4090 x16 : 43.2 seconds @ 48 GPU/56 mem Celcius (13.94 sec prep-time)
• 4090 x4 : 43.7 seconds @ 46 GPU/54 mem Celcius (16.89 sec prep-time)
• 4090 x16 + 3090 x4 : 30.2 seconds @ 48 GPU/56 mem + 61 GPU/58 mem
• 4090 x16 + 4090 x4 : 27.0 seconds @ 44 GPU/56 mem + 44 GPU/54 mem (18.63 sec prep-time)

Bending the connectors :


PCIe-16x slots 1 and 3 used for the GPU's :


Sidepanel lasercutted :


The holes used to guide the power-cables :


The sidepanel with the cords :


Fan-layout :


Aluminium plate to prevent air blown out prematurely :


Gap underneath second GPU :


The external PSU :

Final words :

I'm very happy with the performance considering the amount of money that I DIDN'T spend.
Would I consider upgrading my CPU and as a consequence the mobo/memory: No.
Would I consider upgrading memory 64Gb -> 128Gb : Yes.
Would I consider watercooling and as a consequence using x8 x8 instead of x16 x4 : No, because the temps are better than good !

The noise of the Silent Wings 4 Pro that are set to "high-speed" is present in the room when there's no music. They spin-up "randomly" but mostly when the GPU's start to render, but not always. Anyway, with music there are no noice issues at all.

Lasercutting won't be possible for many : having the PSU where it should be in the case might have a negative effect on the thermals of the second GPU, because the air volume reaching the GPU will be less than it is now.


Future :

There's talk of a 4xxx Titan-version with 40Gb.

Would I consider it : Yes, but only if it can work its magic at no more than 300W using undervolt or Power limit settings in MSI Afterburner.
Would I consider a Quadro/Pro-card : No, too expensive.

I don't make any profit using this workstation. It's a hobby. But FUN !!!!

Quad said:

Replaced both 3090 FE with 4090 FE : they are LITERALLY about twice as fast and they run a lot cooler

Click to expand...

That's what I'm talking about

Quad said:

• 4090 x16 : 43.2 seconds @ 48 GPU/56 mem Celcius (13.94 sec prep-time)
• 4090 x4 : 43.7 seconds @ 46 GPU/54 mem Celcius (16.89 sec prep-time)

Click to expand...

Very interesting! So data upload to GPU is throttled at x4.

Quad said:

Would I consider upgrading memory 64Gb -> 128Gb : Yes.

Click to expand...

Yes this would be the next logical step.

Quad said:

I don't make any profit using this workstation. It's a hobby. But FUN !!!!

Click to expand...

Awesome!

Quad said:

Would I consider watercooling and as a consequence using x8 x8 instead of x16 x4 : No, because the temps are better than good !

Click to expand...

Would you consider x8 x8 due to x4 throttling on data upload to GPU? (preparation time)



Fantastic Posts, thanks for sharing!

"Proof"

Alex Glawion said:

Would you consider x8 x8 due to x4 throttling on data upload to GPU? (preparation time)

Click to expand...

No, it would probably cost me too much to convert to watercooling.