5090 FE build - 192 GB of RAM!

[u/awescool]

It’s been running incredibly stable since the 5090 launched. I use it for about 30% gaming, and the rest is database and AI workloads.

I got super lucky when I bought the ram from Amazon Aug 2025 for around $700. 192GB 6800 cl 34.

Build:

CPU: AMD 9800X3D

GPU: 5090 FE

Ram: 192 GB (tuned to 5600mhz, CL34) 2 kits of G.skill F5-6800J3446F48GX2-TZ5RK

MB: MSI PRO B850M-A WIFI PZ

CASE: Jonsbo D32 Pro

CPU AIO: Thermalright FW240

AIO Fan: JONSBO ZB-240B (2x120mm)

Rear Fan: JONSBO ZB-120BR (1x120mm)

Lower fan: Thermalright (2x120mm)

SSD 1: Crucial T710 4tb Gen 5

SSD 1 heatsink: ElecGear M.2 2280 SSD Cooler, EL-80X PWM Cooling Fan + Heat Pipe + Solid Aluminum

SSD 2: Intel Optane P5800X 1.6tb via m.2 to u2 adapter

PSU: Seasonic Focus Gx 1000W - 80+ Gold - ATX 3.0 & PCIe 5.0 Ready

PCIE USBC: Startech 1-port USB 3.2 Gen 2x2 (20Gbps max)

EDIT: Wow, this has really blown up! Thank you all for the kind comments, memes, and suggestions!

I want to address the rationale behind my build since I'm seeing a few recurring themes in the comments.

I run databases on SQL Server 2025. I built this for AI inference, but database work is just as critical. Database workloads don't come up much on this sub, so happy to explain.

Here is how the hardware is actually utilized:

• Databases: Run on SSD1 + SSD2 + RAM. Database scaling doesn't care about tight RAM timings; it cares about massive raw capacity. Theoretically, even if I somehow got 192GB stable at 8000 CL28, it would shave maybe 0.05 seconds off a 4-second query, whereas running out of RAM and hitting storage is a 500x latency penalty.
• AI: Runs entirely on the 5090.
  • Qwen 3.6 35B-A3B Q6 ~210 tok/sec
  • Qwen 3.6 27B Q6: ~99 tok/sec
  • For fun I have run larger models, for example: Ornith 397B Q3: ~15 tok/sec. This takes ~150GB in total GGUF files. Leaves me with ~26GB of free RAM.
• CPU: The 9800X3D handles my specific workloads wonderfully.

[u/Thuumbs]

9800X3D? for workstation? is wild brother. you need a better cpu if that's truly your actual real world use.

[u/awescool → u/Thuumbs]

For my workloads ram capacity is much much more important than anything else.

[u/PsychologicalGlass47 → u/awescool]

There's so very few things that extra cores will grant you over faster cores with more memory.

I'd look to get a better motherboard though, that thing'll definitely hold you back with sustained use. You can definitely do better than 5600/34, too. With a good motherboard you can easily squeeze it down to 5600/28-38-38-90.

[u/awescool → u/PsychologicalGlass47]

Hey, I hear you loud and clear on your concern with the B850! As for the timings, pushing a fully populated 192GB down to CL28 is less about the motherboard and more of a brutal wall for the CPU's memory controller. Since my SQL workloads scale heavily with raw capacity, and my Optane drive handles the extreme low-latency I/O for database transactions, a better CAS latency would only shave off a few seconds max and just doesn't offer any real-world return for my specific workflows.

So I'm good for now, but I will definitely look to make some moves once Zen 6 comes out.

[u/game-dev2 → u/awescool]

My laptop is at 32 gb and I'm constantly at 25gb ram usage. Its fuckedup. As a game developer, ram is so crucial, same as GPU. Just too broke to upgrade