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GPT-5.5vsSolar Open 2 250B-A15B

GPT-5.5 leads 3 of 3 shared benchmarks. Both offer a 1M-token context window.

Benchmarks from cited public sources; pricing from official pages; status from official provider feeds.

Shared benchmarks
3 – 0
GPT-5.5 leads
Cheaper per token
list price, input + output
Larger context
Tie
both 1M tokens
Provider uptime (30d)
94.9045% · —
OpenAI · Upstage
GPT-5.5
OpenAI · released 2026-04-23
textvision
Context
1M
Max out
128K
Input /1M
$5
Output /1M
$30
Cached /1M
$0.5
Scores
21 · 10 core
Solar Open 2 250B-A15B
Upstage · released 2026-07-24
text
Context
1M
Max out
Input /1M
Output /1M
Cached /1M
Scores
16 · 5 core
Quality

Benchmark matrix

BenchmarkGPT-5.5Solar Open 2 250B-A15BΔEdge
Reported by both · 3
GPQA Diamond90.7% epoch86.3% +4.4 ptGPT-5.5
AIME 2026100% matharena95.7% +4.3 ptGPT-5.5
MCP Atlas75.3% 58.2% +17.1 ptGPT-5.5
Only GPT-5.5 reports · 18
LMArena Elo1465.6 not reported
ARC-AGI-1 (Verified)95% not reported
ARC-AGI-2 (Verified)85% not reported
BrowseComp84.4% not reported
FrontierMath Tier 1-351.7% not reported
FrontierMath Tier 435.4% not reported
FrontierMath Tier 4 v2 (Epoch AI run)72.5% epochnot reported
FrontierMath Tiers 1-3 v2 (Epoch AI run)85.3% epochnot reported
GDPval (wins or ties)84.9% not reported
MMMU-Pro (no tools)81.2% not reported
MMMU-Pro (with tools)83.2% not reported
OSWorld-Verified78.7% not reported
OTIS Mock AIME 2024-2025 (Epoch AI run)84.4% epochnot reported
SimpleQA Verified63% epochnot reported
SWE-Bench Pro58.6% not reported
Tau2-bench Telecom98% not reported
Terminal-Bench 2.082.7% not reported
Toolathlon55.6% not reported
Only Solar Open 2 250B-A15B reports · 13
SWE-bench Verifiednot reported70.4%
MMLU-Pronot reported86.2%
Humanity's Last Exam (no tools)not reported28.8%
AA-LCRnot reported62.3%
APEX-Agentsnot reported16.6%
ArtifactsBenchnot reported55.9%
GDPval-AA v2not reported1128
HMMT 2026-02not reported93.9%
IFBenchnot reported80%
LiveCodeBench v6not reported92.4%
Multi-Challengenot reported61%
Tau3-Bench (banking)not reported19.6%
Terminal Bench Hardnot reported28.3%
Scores tagged "epoch" or "matharena" are independent runs, used only where the lab has not published its own; ⚠ marks rows MathArena flags as released after the competition. Higher is better on every row. Δ is GPT-5.5 minus Solar Open 2 250B-A15B in the benchmark's own unit. "Not reported" means the lab has not published that figure; it is not a zero. ↗ opens the source.
Specs & pricing

Side by side

SpecGPT-5.5Solar Open 2 250B-A15BEdge
Context window1M tokens1M tokensTie
Max output128K tokens
Input price / 1M$5
Output price / 1M$30
Cached input / 1M$0.5
Input + output / 1M
Lower is cheaper. List prices; batch, tool and regional fees excluded.
$35
Modalitiestext · visiontextGPT-5.5
Released2026-04-232026-07-24
Cited benchmark scores2116
Reliability

Provider status

All providers
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