desktop tower: replace RTX 2080 with used RTX 3090 24GB #85

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opened 2026-05-23 20:54:40 +00:00 by coilysiren · 1 comment

coilysiren commented

2026-05-23 20:54:40 +00:00

Owner

Originally filed by @coilysiren on 2026-04-29T01:23:56Z - https://github.com/coilysiren/infrastructure/issues/75

🤖 Filed by Claude Code on Kai's behalf.

Goal

Replace the desktop tower's RTX 2080 (8GB Turing) with a used RTX 3090 (24GB Ampere) so the box can run local LLM inference at meaningful scale. 24GB of VRAM unlocks 13B models at full precision, 30B-class quantized, and 70B at aggressive quant. The 8GB ceiling on the 2080 caps everything at ~7B and rules out most current open-weights models.

Card target

Primary: EVGA RTX 3090 FTW3 Ultra Gaming (24G-P5-3987-KR). 4.6 ⭐ / 987 reviews on Amazon - strongest review signal of any 3090 SKU. Triple-fan AIB cooler, well-binned, ARGB, metal backplate. EVGA exited the GPU business in 2022 so manufacturer warranty support is gone, which makes the seller-side warranty (eBay buyer protection / Newegg refurb / Micro Center return) the load-bearing protection.

Fallback: NVIDIA RTX 3090 Founders Edition. More compact (dual-slot vs FTW3's 2.7-slot), lower TDP (350W vs 400W), tidier aesthetics. Take whichever shows up cheaper from a trustworthy seller.

Skip: RTX 3090 Ti. Costs $400-500 more, draws 50W more, marginal local-AI gain. 3090 is the value sweet spot.

Where to buy

Ranked by price/risk tradeoff:

eBay with these filters: Used + Seller refurbished, 99%+ feedback, 1,000+ ratings, "non-mining" or "gaming use only" in description. Realistic price $750-900. filtered search
Newegg refurbished, currently out of stock on the FTW3 SKU - check weekly. Expect $900-1,100 with 30-90 day warranty when restocked. product page
Micro Center used (in-store) - Tustin or Concord, both ~1-2hr drives. Best return policy, requires the trip.
Skip Amazon Renewed. Researched 4/28/26: $1,349-$1,995 for the same cards available elsewhere for $750-1,100. The 90-day Renewed Guarantee is real but the markup is too high.

April 2026 market reference data

eBay average: $700-800
12-month range: $699-$1,125
Newegg refurb (when in stock): $900-1,100
Amazon Renewed: $1,349-$1,995 (overpriced)
Sources: Best Value GPU tracker, XDA local-AI guide

Hard dependency: PSU upgrade

RTX 2080 draws ~225W; RTX 3090 wants 350W typical, 400W on the FTW3 under load. Existing PSU is sized for the 2080 (probably 650W) and is undersized for a 3090. Need 850W 80+ Gold minimum with at least 2x PCIe 8-pin (3x for FTW3). PSU swap and GPU swap should happen in the same install session.

Tracking PSU separately - will link the issue once filed.

Acceptance

PSU upgrade landed (separate issue).
3090 acquired from a trusted seller for $750-1,100.
Old RTX 2080 removed, 3090 seated, all PCIe power cables connected.
First boot: Windows recognizes the card, NVIDIA driver installed.
nvidia-smi shows 24GB VRAM available.
Test load: a 13B model in llama.cpp or similar runs fully on GPU.
desktop-tower.md GPU + PSU sections updated.
RTX 2080 boxed up for resale or hand-off (don't toss).

refs #73 (evaluate self-hosted models on desktop tower) - this is the hardware lever for that issue.
refs #74 (NVMe SSD) - SSD speeds up GGUF loads from disk; 3090 is what runs them once loaded.

🤖 Filed by Claude Code on Kai's behalf.

_Originally filed by @coilysiren on 2026-04-29T01:23:56Z - [https://github.com/coilysiren/infrastructure/issues/75](https://github.com/coilysiren/infrastructure/issues/75)_ > 🤖 Filed by Claude Code on Kai's behalf. ## Goal Replace the desktop tower's RTX 2080 (8GB Turing) with a used RTX 3090 (24GB Ampere) so the box can run local LLM inference at meaningful scale. 24GB of VRAM unlocks 13B models at full precision, 30B-class quantized, and 70B at aggressive quant. The 8GB ceiling on the 2080 caps everything at ~7B and rules out most current open-weights models. ## Card target **Primary:** EVGA RTX 3090 FTW3 Ultra Gaming (`24G-P5-3987-KR`). 4.6 ⭐ / 987 reviews on Amazon - strongest review signal of any 3090 SKU. Triple-fan AIB cooler, well-binned, ARGB, metal backplate. EVGA exited the GPU business in 2022 so manufacturer warranty support is gone, which makes the seller-side warranty (eBay buyer protection / Newegg refurb / Micro Center return) the load-bearing protection. **Fallback:** NVIDIA RTX 3090 Founders Edition. More compact (dual-slot vs FTW3's 2.7-slot), lower TDP (350W vs 400W), tidier aesthetics. Take whichever shows up cheaper from a trustworthy seller. **Skip:** RTX 3090 Ti. Costs $400-500 more, draws 50W more, marginal local-AI gain. 3090 is the value sweet spot. ## Where to buy Ranked by price/risk tradeoff: 1. **eBay** with these filters: `Used + Seller refurbished`, 99%+ feedback, 1,000+ ratings, "non-mining" or "gaming use only" in description. Realistic price **$750-900**. [filtered search](https://www.ebay.com/sch/i.html?_nkw=evga+rtx+3090+ftw3&LH_ItemCondition=3000%7C2030&_sop=15) 2. **Newegg refurbished**, currently out of stock on the FTW3 SKU - check weekly. Expect **$900-1,100 with 30-90 day warranty** when restocked. [product page](https://www.newegg.com/evga-ftw3-24g-p5-3987-kr-geforce-rtx-3090-24gb-graphics-card-triple-fans/p/1FT-001K-00FE0) 3. **Micro Center used (in-store)** - Tustin or Concord, both ~1-2hr drives. Best return policy, requires the trip. 4. **Skip Amazon Renewed.** Researched 4/28/26: $1,349-$1,995 for the same cards available elsewhere for $750-1,100. The 90-day Renewed Guarantee is real but the markup is too high. ## April 2026 market reference data - eBay average: $700-800 - 12-month range: $699-$1,125 - Newegg refurb (when in stock): $900-1,100 - Amazon Renewed: $1,349-$1,995 (overpriced) - Sources: [Best Value GPU tracker](https://bestvaluegpu.com/history/new-and-used-rtx-3090-price-history-and-specs/), [XDA local-AI guide](https://www.xda-developers.com/used-rtx-3090-still-best-for-local-ai-in-value/) ## Hard dependency: PSU upgrade RTX 2080 draws ~225W; RTX 3090 wants 350W typical, 400W on the FTW3 under load. Existing PSU is sized for the 2080 (probably 650W) and is **undersized** for a 3090. Need **850W 80+ Gold minimum** with at least 2x PCIe 8-pin (3x for FTW3). PSU swap and GPU swap should happen in the same install session. Tracking PSU separately - will link the issue once filed. ## Acceptance - [ ] PSU upgrade landed (separate issue). - [ ] 3090 acquired from a trusted seller for $750-1,100. - [ ] Old RTX 2080 removed, 3090 seated, all PCIe power cables connected. - [ ] First boot: Windows recognizes the card, NVIDIA driver installed. - [ ] `nvidia-smi` shows 24GB VRAM available. - [ ] Test load: a 13B model in llama.cpp or similar runs fully on GPU. - [ ] `desktop-tower.md` GPU + PSU sections updated. - [ ] RTX 2080 boxed up for resale or hand-off (don't toss). ## Related - refs #73 (evaluate self-hosted models on desktop tower) - this is the hardware lever for that issue. - refs #74 (NVMe SSD) - SSD speeds up GGUF loads from disk; 3090 is what runs them once loaded. > 🤖 Filed by Claude Code on Kai's behalf.

coilysiren referenced this issue

2026-05-25 21:24:57 +00:00

Title: desktop tower: verify case fan airflow direction before 3090 install #124

coilysiren commented

2026-05-30 05:43:28 +00:00

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Owner

Iceboxed in the 2026-05-29 backlog burn-down: buy used RTX 3090 hardware toy. Reopen anytime if it becomes real.

coilysiren closed this issue

2026-05-30 05:43:28 +00:00

coilysiren referenced this issue

2026-06-01 03:55:30 +00:00