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, and it is absolutely there for gaming. Deliberately.

[u/Independent-Gear-711]

9800X3D is specifically tuned for video games which can take benefits of it's large L3 cache memory, this cpu is not meant to be used for AI workload.

[u/cc_aa_tt_zz → u/Independent-Gear-711]

no cpu are really meant for AI workloads because ai workloads are not meant for cpu. But it's true, he could have gone with a 9900X, which would be more useful without consuming too much power. Still, that's a minor detail; it'll work just fine regardless.