{
  "slug": "solar-open-2",
  "order": 92,
  "name": "Solar Open 2 (250B)",
  "baseTitle": "Solar Open 2",
  "company": "Upstage",
  "country": "South Korea",
  "flag": "🇰🇷",
  "date": "2026-07-22",
  "decoderType": "Sparse hybrid",
  "attention": "3:1 Kimi Delta Attention and gated GQA with NoPE",
  "layerMix": "12 gated GQA + 36 Kimi Delta Attention",
  "scale": "250B total, 15B active (6% active)",
  "totalParams": 250000000000,
  "activeParams": 15000000000,
  "context": "1,048,576",
  "contextTokens": 1048576,
  "license": "Upstage Solar License",
  "kvCacheText": "48 KiB",
  "kvCacheKiB": 48,
  "kvCacheLevel": "Low",
  "summary": "Upstage's sparse hybrid alternates one gated GQA layer with three Kimi Delta Attention layers and reaches a 1M-token context without positional embeddings.",
  "keyDetail": "Uses a repeating gated-GQA/KDA hybrid stack, kernel-4 ShortConv in KDA, and top-8 routing over 320 experts plus one shared expert.",
  "image": {
    "full": "https://sebastianraschka.com/llm-architecture-gallery/images/architectures/solar-open-2.webp",
    "thumb": "https://sebastianraschka.com/llm-architecture-gallery/images/architectures/thumbnails/solar-open-2.webp",
    "alt": "Figure 1: Solar Open 2",
    "width": 960,
    "height": 714
  },
  "articleUrl": null,
  "links": [
    {
      "label": "config.json",
      "href": "https://huggingface.co/upstage/Solar-Open2-250B/blob/main/config.json",
      "title": "upstage/Solar-Open2-250B"
    },
    {
      "label": "License",
      "href": "https://huggingface.co/upstage/Solar-Open2-250B/blob/main/LICENSE",
      "title": null
    },
    {
      "label": "Tech report",
      "href": "https://huggingface.co/upstage/Solar-Open2-250B/blob/main/Solar_Open_2_Tech_Report.pdf",
      "title": null
    }
  ],
  "concepts": [
    {
      "slug": "gqa",
      "label": "GQA",
      "name": "Grouped-Query Attention",
      "url": "https://llm-atlas-7or.pages.dev/concepts/gqa/"
    },
    {
      "slug": "gated-attention",
      "label": "Gated Attention",
      "name": "Gated Attention",
      "url": "https://llm-atlas-7or.pages.dev/concepts/gated-attention/"
    },
    {
      "slug": "hybrid-attention",
      "label": "Hybrid Attention",
      "name": "Hybrid Attention",
      "url": "https://llm-atlas-7or.pages.dev/concepts/hybrid-attention/"
    },
    {
      "slug": "shortconv",
      "label": "ShortConv",
      "name": "Short Convolution",
      "url": "https://llm-atlas-7or.pages.dev/concepts/shortconv/"
    },
    {
      "slug": "nope",
      "label": "NoPE",
      "name": "No Positional Embeddings",
      "url": "https://llm-atlas-7or.pages.dev/concepts/nope/"
    },
    {
      "slug": "moe",
      "label": "MoE",
      "name": "Mixture of Experts",
      "url": "https://llm-atlas-7or.pages.dev/concepts/moe/"
    }
  ],
  "aai": {
    "v4": {
      "label": "AA Intelligence Index v4.3.2",
      "total": 24.7,
      "profile": {
        "Scientific": 17.1
      },
      "url": "https://artificialanalysis.ai/models/solar-open2-250b"
    }
  },
  "sourceUrl": "https://sebastianraschka.com/llm-architecture-gallery/#card-solar-open-2",
  "family": "hybrid-moe",
  "url": "https://llm-atlas-7or.pages.dev/models/solar-open-2/",
  "markdownUrl": "https://llm-atlas-7or.pages.dev/models/solar-open-2.md"
}