High-end build · open-frame · Used parts

FJÄLLBO

AI workstation arranged on an IKEA table

Built by r/LocalLLaMA community member · Source: r/LocalLLaMA: 4x 3090 local AI workstation · Updated October 14, 2026

Open-air AI rig built around a small white IKEA table, with MSI Suprim RTX 3090 cards on top and on the floor, the motherboard underneath, and several power supplies with thick cable bundles beside it.

Total cost: $6,486
VRAM: 96GB
GPUs: 4
System RAM: 128GB

What can this build run?

With 96GB of VRAM across 4 GPUs, this build comfortably runs models up to Qwen3.5 122B-A10B (Q4_K_M, ~39 tokens/sec). Our top all-round pick for it is Qwen3.8 27B at Q8_0 (~21 tokens/sec).

Parts list

Every part in the FJÄLLBO

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Part	Price	Buy
GPU 4×NVIDIA GeForce RTX 3090 (used)	$3,400$850 each	eBay
CPU AMD Ryzen Threadripper PRO 3955WX	$600	Amazon
CPU Cooler ARCTIC Liquid Freezer III	$89	Amazon
Motherboard ASUS Pro WRX80E-SAGE	$1,199	Amazon
Memory Remix Ram DDR4 128GB	$456	Amazon
Storage Samsung 980 Pro 2TB M.2-2280 NVMe SSD	$199	Amazon
Case IKEA FJÄLLBO table	$45
Power Supply CORSAIR HX1500i 1500W	$698	Amazon
Total	$6,486

Listed prices from 2025; check current prices. The builder paid about $4,300 in total by buying everything used. Individual parts add up to $6,686.

Capability

Models this build runs well

Estimated for a single user with 8K context, with the model split across all GPUs (for example with llama.cpp). Best quantization that fits, ranked by our capability score.

Best overall · also coding, reasoning, vision
Qwen3.8 27B
Q8_0 · ~21 tokens/sec
Runner-up · also largest that fits
Qwen3.5 122B-A10B
Q4_K_M · ~39 tokens/sec
Fastest good model
gpt-oss-20b
MXFP4 · ~60 tokens/sec

Model	Quant	Speed	Fit
Qwen3.8 27B	Q8_0	~21 tok/s	Runs well
Qwen3.5 122B-A10B	Q4_K_M	~39 tok/s	Runs well
Qwen3.6 35B-A3B	Q8_0	~52 tok/s	Runs well
Gemma 4 31B	Q8_0	~19 tok/s	Runs well
gpt-oss-120b	MXFP4	~56 tok/s	Runs well
Gemma 4 26B A4B	Q8_0	~48 tok/s	Runs well
GLM-4.5-Air	Q5_K_M	~31 tok/s	Runs well
gpt-oss-20b	MXFP4	~60 tok/s	Runs well
Qwen3.5 9B	Q8_0	~48 tok/s	Runs well
Gemma 4 E4B	Q8_0	~53 tok/s	Runs well

The build

About this build

Four used RTX 3090s on an open IKEA table give this Threadripper PRO rig 96GB of VRAM for running 70B-class models locally. The builder bought every part on the used market for about $4,300.

Why this build

I bought everything on the used market, about $4,300 in total, and got 96GB of VRAM. I’m currently considering picking up two more 3090s and maybe one 5090, but I think the current price of 3090s makes them a great deal for building a local AI workstation.

Notes and caveats

The $4,300 figure is what the builder actually paid for used parts. The parts list totals $6,486 at the prices we listed when we added the build.
The “case” is an IKEA FJÄLLBO table, so everything runs open-air.