Single GPU · DIY build
1x RTX 5090
The fastest single consumer card: 32 GB of GDDR7 at 1.79 TB/s. It fits 32B dense models at 8-bit or 70B at about 3 bits.
Memory for models
VRAM
Memory bandwidth
Parts
GPU price not included
gpt-oss-20b, 4-bit
Parts
| Part | Qty | Each |
|---|---|---|
| GPUNVIDIA GeForce RTX 5090 | 1 | not priced |
| CPUAMD Ryzen 9 9950X (16-core, 170 W) | 1 | ~$649 |
| MotherboardASUS TUF GAMING X870E-PLUS WIFI7 | 1 | ~$325 |
| RAMCorsair Vengeance 64GB (2x32GB) DDR5-6000 CL30 | 1 | ~$1,275 |
| PSUCorsair RM1000x (1000 W) | 1 | ~$210 |
| CaseCorsair 7000D AIRFLOW full tower (450 mm GPU clearance, 8 slots) | 1 | ~$290 |
| StorageCorsair MP600 CORE XT 2TB PCIe 4.0 NVMe | 1 | ~$485 |
| Priced parts only | $3,234GPU price not included | |
New parts are priced at the maker’s own store or list price. Used cards have no price here yet, and a total with a missing GPU would understate the build, so none is shown.
What it runs at 4-bit
Every model in the catalog at its 4-bit file with 8,192 tokens of context. 20 of 41 fit. Speeds are the median of measured runs on the same GPUs where any exist; otherwise an estimate from memory bandwidth. Try other quants and context lengths.
| Model | Needs | Fit | Generation speed |
|---|---|---|---|
| Kimi K32.8T, 104B active · UD-Q4_K_XL | 1406.8 GBcontext memory estimated | Does not fit | |
| DeepSeek V4 Pro1.6T, 49B active · Q4_K_M | 890.5 GBcontext memory not counted | Does not fit | |
| Kimi K2.61T, 32B active · UD-Q4_K_XL | 545.7 GBcontext memory estimated | Does not fit | |
| DeepSeek V4.1 Flash552B, 16B active · Q4 (DwarfStar) | 484.5 GB | Does not fit | |
| GLM-5.3753.3B · UD-Q4_K_XL | 437.4 GBcontext memory estimated | Does not fit | |
| DeepSeek V3.2671B, 37B active · Q4_K_M | 379.6 GBcontext memory estimated | Does not fit | |
| MiniMax M3428B, 23B active · Q4_K_M | 244.8 GBcontext memory not counted | Does not fit | |
| Qwen3.5 397B-A17B397B, 17B active · Q4_K_M | 229.1 GBcontext memory estimated | Does not fit | |
| GLM-5.3 Flash320B, 18B active · UD-Q4_K_XL | 187.6 GBcontext memory estimated | Does not fit | |
| Hy3295B, 21B active · Q4_K_M | 173.6 GB | Does not fit | |
| MiniMax M2.7228.7B · Q4_K_M | 132.7 GB | Does not fit | |
| Qwen3.8 Flash-Next125B, 6B active · Q4_K_M | 113.1 GBcontext memory estimated | Does not fit | |
| Nemotron 3 Super 120B-A12B120B, 12B active · Q4_K_M | 82.6 GBcontext memory estimated | Does not fit | |
| Qwen3.5 122B-A10B122B, 10B active · Q4_K_M | 73.0 GBcontext memory estimated | Does not fit | |
| Mistral Medium 3.5 128B128B · Q4_K_M | 74.0 GB | Does not fit | |
| GLM-4.5-Air106B, 12B active · Q4_K_M | 70.9 GB | Does not fit | |
| Mistral Small 4 119B (2603)119B, 6.5B active · Q4_K_M | 69.3 GBcontext memory estimated | Does not fit | |
| Llama 4 Scout 17B-16E Instruct109B, 17B active · Q4_K_M | 62.4 GBcontext memory not counted | Does not fit | |
| gpt-oss-120b117B, 5.1B active · MXFP4 (native) | 60.2 GBcontext memory estimated | Does not fit | |
| Qwen3 Coder Next80B, 3B active · Q4_K_M | 46.9 GBcontext memory estimated | Does not fit | |
| Llama 3.3 70B Instruct70B · Q4_K_M | 43.6 GB | Does not fit | |
| Nemotron 3.5 Lightning 30B-A3B30B, 3B active · Q4_K_M | 25.3 GBcontext memory estimated | Fits | ~175–256 tok/sestimate |
| Qwen3.6 35B-A3B35B, 3B active · Q4_K_M | 22.4 GBcontext memory estimated | Fits | 117 tok/smedian of 1 run |
| Ornith 1.5 35B-A3B35B, 3B active · Q4_K_M | 21.9 GBcontext memory estimated | Fits | ~240–350 tok/sestimate |
| Qwen3 Coder 30B-A3B Instruct30.5B, 3.3B active · Q4_K_M | 19.5 GB | Fits | ~222–324 tok/sestimate |
| Gemma 4 31B IT30.7B · Q4_K_M | 18.9 GBcontext memory estimated | Fits | 61 tok/smedian of 1 run |
| Granite 4.2 30B29.3B · Q4_K_M | 20.3 GB | Fits | ~49–77 tok/sestimate |
| Qwen3.8 27B27B · Q4_K_M | 18.2 GBcontext memory estimated | Fits | ~50–79 tok/sestimate |
| Gemma 4 26B-A4B IT25.2B, 3.8B active · Q4_K_M | 17.4 GBcontext memory estimated | Fits | 122 tok/smedian of 2 runs |
| Qwen3.6 27B27B · Q4_K_M | 17.7 GBcontext memory estimated | Fits | ~52–82 tok/sestimate |
| Devstral Small 2 24B (2512)24B · Q4_K_M | 16.1 GB | Fits | ~61–96 tok/sestimate |
| gpt-oss-20b21B, 3.6B active · MXFP4 (native) | 12.5 GBcontext memory estimated | Fits | 290 tok/smedian of 4 runs |
| Phi-414.7B · Q4_K_M | 11.3 GB | Fits | ~99–155 tok/sestimate |
| Ministral 3 14B Reasoning (2512)13.9B · Q4_K_M | 10.4 GB | Fits | ~107–167 tok/sestimate |
| Gemma 4 12B IT11.95B · Q4_K_M | 8.2 GBcontext memory estimated | Fits | ~123–194 tok/sestimate |
| Qwen3.5 9B9B · Q4_K_M | 7.0 GBcontext memory estimated | Fits | ~155–243 tok/sestimate |
| Granite 4.2 8B8.8B · Q4_K_M | 7.9 GB | Fits | ~159–249 tok/sestimate |
| Gemma 4 E4B IT8B · Q4_K_M | 6.5 GBcontext memory not counted | Fits | ~289–454 tok/sestimate |
| Qwen3 8B8.2B · Q4_K_M | 7.3 GB | Fits | 200 tok/smedian of 1 run |
| Llama 3.1 8B Instruct8B · Q4_K_M | 7.1 GB | Fits | 200 tok/smedian of 3 runs |
| Qwen3.5 4B4B · Q4_K_M | 4.3 GBcontext memory estimated | Fits | ~321–503 tok/sestimate |
Measured speeds
15 published runs with one user, plain decoding and at most 4,096 tokens already in context, on RTX 5090. Runs on RTX 5090 + EPYC 9355P with 768 GB DDR5 (MoE offload) with the same GPUs count here too, and say so.
| Model | Quant | Backend | Generation | Prompt | Context | Measured on | Source |
|---|---|---|---|---|---|---|---|
| Gemma 4 26B-A4B IT | Q4_K | llama.cpp (build not stated) | 180 tok/s | 8,799 tok/s4,096-token prompt | 4,096 | RTX 5090 | review2026-03 |
| Gemma 4 26B-A4B IT | INT4 experts / HQQ4 attention / k4v4 KV | Krasis (MoE runtime; version not stated in table) | 64 tok/s | 5,599 tok/s | 0 | RTX 5090 | independent benchmark2026-10 |
| Gemma 4 31B IT | Q4_K | llama.cpp (build not stated) | 61 tok/s | 3,395 tok/s4,096-token prompt | 4,096 | RTX 5090 | review2026-03 |
| gpt-oss-20b | MXFP4 MoE | llama.cpp b6782 CUDA,BLAS | 299 tok/s | 13,002 tok/s2,048-token prompt | 0 | RTX 5090 | llama.cpp benchmark discussion2025-10 |
| gpt-oss-20b | Q4_K | llama.cpp (build not stated) | 298 tok/s | 9,444 tok/s4,096-token prompt | 4,096 | RTX 5090 | review2026-03 |
| gpt-oss-20b | MXFP4 MoE | llama.cpp b6210 CUDA | 283 tok/s | 9,848 tok/s2,048-token prompt | 0 | RTX 5090 | llama.cpp benchmark discussion2025-08 |
| gpt-oss-20b | MXFP4 | Ollama (version not stated) | 205 tok/s | 8,519 tok/s | 0 | RTX 5090 | review2025-10 |
| Llama 3.1 8B Instruct | Q4_K_M | llama.cpp b11741 | 278 tok/s | – | 0 | RTX 5090 | review2026-10 |
| Llama 3.1 8B Instruct | Q4_K_M | Ollama (version not stated) | 200 tok/s | 30,982 tok/s | 0 | RTX 5090 | review2025-10 |
| Llama 3.1 8B Instruct | Q4_K_M | LocalScore (llamafile; version not stated on leaderboard) | 66 tok/s | 6,297 tok/s | 0 | RTX 5090 | LocalScore2026-10 |
| Llama 3.1 8B Instruct | Q8_0 | Ollama (version not stated) | 145 tok/s | 31,442 tok/s | 0 | RTX 5090 | review2025-10 |
| Llama 3.1 8B Instruct | FP8 | SGLang (lmsysorg/sglang:spark image) | 138 tok/s | 21,956 tok/s2,048-token prompt | 0 | RTX 5090 | review2025-10 |
| Llama 3.3 70B Instruct | IQ3_XXS | llama.cpp b11741 | 53 tok/s | – | 0 | RTX 5090 | review2026-10 |
| Qwen3 8B | Q4_K | llama.cpp b8189 | 200 tok/s | 11,933 tok/s4,096-token prompt | 4,096 | RTX 5090 | review2026-03 |
| Qwen3.6 35B-A3B | INT4 experts / HQQ4 attention / k4v4 KV | Krasis (MoE runtime; version not stated in table) | 117 tok/s | 10,670 tok/s | 0 | RTX 5090 | independent benchmark2026-10 |
With speculative decoding
A small draft model or extra prediction heads guess several tokens ahead. Generation is faster on text the guesses get right, so these are kept out of the medians above.
| Model | Quant | Backend | Generation | Prompt | Context | Measured on | Source |
|---|---|---|---|---|---|---|---|
| Qwen3.8 27B | NVFP4 (native, NVFP4 KV) | vLLM 0.27.1 + heavy local patches | 101 tok/s | – | 0 | RTX 5090 | independent benchmark2026-08 |
Deep into a long context
Measured with more than 4,096 tokens already in context, where every new token also reads the context memory.
| Model | Quant | Backend | Generation | Prompt | Context | Measured on | Source |
|---|---|---|---|---|---|---|---|
| Gemma 4 26B-A4B IT | Q4_K | llama.cpp (build not stated) | 167 tok/s | 7,733 tok/s16,384-token prompt | 16,384 | RTX 5090 | review2026-03 |
| Gemma 4 26B-A4B IT | Q4_K | llama.cpp (build not stated) | 159 tok/s | 6,293 tok/s32,768-token prompt | 32,768 | RTX 5090 | review2026-03 |
| Gemma 4 31B IT | Q4_K | llama.cpp (build not stated) | 59 tok/s | 2,794 tok/s16,384-token prompt | 16,384 | RTX 5090 | review2026-03 |
| Gemma 4 31B IT | Q4_K | llama.cpp (build not stated) | 55 tok/s | 2,229 tok/s32,768-token prompt | 32,768 | RTX 5090 | review2026-03 |
| gpt-oss-20b | Q4_K | llama.cpp (build not stated) | 249 tok/s | 7,168 tok/s16,384-token prompt | 16,384 | RTX 5090 | review2026-03 |
| gpt-oss-20b | Q4_K | llama.cpp (build not stated) | 215 tok/s | 5,183 tok/s32,768-token prompt | 32,768 | RTX 5090 | review2026-03 |
| Qwen3 8B | Q4_K | llama.cpp b8189 | 162 tok/s | 8,538 tok/s16,384-token prompt | 16,384 | RTX 5090 | review2026-03 |
| Qwen3 8B | Q4_K | llama.cpp b8189 | 130 tok/s | 6,034 tok/s32,768-token prompt | 32,768 | RTX 5090 | review2026-03 |
Specifications
- GPUs
- 1 × NVIDIA GeForce RTX 5090
- VRAM
- 32 GB
- System RAM
- 64 GB
- RAM bandwidth
- 2 channels x 6000 MT/s x 8 bytes = 96.0 GB/s (dual-channel AM5)
- Power supply
- 1000 W
- Estimated load
- RTX 5090 575 W + Ryzen 9 9950X 170 W + 100 W = 845 W
- Software
- CUDA, Vulkan
Before you build it
- DDR5 prices are at shortage highs: Corsair lists a 64 GB (2x32) DDR5-6000 kit at $1,274.99, so RAM can cost more than a used GPU.
- NVIDIA specifies a 1,000 W PSU for an RTX 5090 system and a single 600 W 12V-2x6 cable (or 4x 8-pin adapter).
Sources
- shop-us-en.amd.com: price of AMD Ryzen 9 9950X (16-core, 170 W)
- eshop.asus.com: price of ASUS TUF GAMING X870E-PLUS WIFI7
- corsair.com: price of Corsair Vengeance 64GB (2x32GB) DDR5-6000 CL30
- corsair.com: price of Corsair RM1000x (1000 W)
- corsair.com: price of Corsair 7000D AIRFLOW full tower (450 mm GPU clearance, 8 slots)
- corsair.com: price of Corsair MP600 CORE XT 2TB PCIe 4.0 NVMe
- nvidia.com: RTX 5090 575 W, 1000 W system PSU
Similar machines
- RTX 5090 + EPYC 9355P with 768 GB DDR5 (MoE offload)~$3,763 + unpriced parts
- 1x RTX 3090 (used)~$2,944 + unpriced parts
- 1x RTX PRO 6000 Blackwell~$20,833