STEALTHMARK · HEAD TO HEAD

All comparisons ↗

GPT-6.1 Terra vs Nemotron 3 Ultra

GPT-6.1 Terra leads Nemotron 3 Ultra by 43.7 points on StealthMark, 60.4 to 16.7. It leads on all 9 benchmarks. GPT-6.1 Terra scores higher on Newton's Mirror, with its largest category advantage in reflections.

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All results ↗
All results ↗

Overall StealthMark

60.4/100Overall rank 9/54
16.7/100Overall rank 50/54

General Intelligence

58.0/100
12.2/100

Visual Intelligence

64.9/100
26.5/100

Reasoning efficiency

On every task, result quality and reasoning tokens are each compared with all measured models and weighed equally. Each dot is one model.

Single-step reasoning Result quality weighed against reasoning tokens on a single problem

Multi-step reasoning Result quality weighed against reasoning tokens across connected steps, as in agentic workflows

BENCHMARK BY BENCHMARK

Where each model leads

  • GPT-6.1 Terra
  • Nemotron 3 Ultra
  • Other models
  • Median

DATASHEET

Specs and pricing

GPT-6.1 Terra scores higher on StealthMark. Nemotron 3 Ultra is 2.1× cheaper per output token. Both take about 1.05M tokens of context.

  • GPT-6.1 Terra
  • Nemotron 3 Ultra
  • Other models
  • Median
PricePer 1M output tokens, input below
GPT-6.1 Terra: $5$1 inputNemotron 3 Ultra: $2.402.1× cheaper$0.60 input
Context windowTokens per request, max output below
GPT-6.1 Terra: 1.05MTied128K max outputNemotron 3 Ultra: 1MTied
Output speedTokens per second, our measurement
GPT-6.1 Terra: Not measuredNemotron 3 Ultra: 139tokens/s
SizeTotal and active parameters
GPT-6.1 Terra: Not disclosedNemotron 3 Ultra: 550B55B active
Developer
OpenAINVIDIA
Released
26 Oct 20264 Jun 2026
Origin
United StatesBoth
Input → output
Text, image → textText → text
Architecture
Not publishedLatentMoE: Mamba-2 + MoE + Attention hybrid with Multi-Token Prediction

Full datasheets, every price and sourceGPT-6.1 Terra ↗Nemotron 3 Ultra ↗

Anticipating threats and planning ahead. Collect coins while avoiding ghosts. Ghosts move before the player each turn, and collisions cost a life. 3 levels in sequence, up to 66 turns in total. Earlier moves and outcomes carry forward, testing learning across levels.

GPT-6.1 Terra 62.0/100Rank 9/50

Survived 2 of 3
Foresight: complete playing field
Level 315 ptsTurn 20 / 20

Nemotron 3 Ultra 16.9/100Rank 44/50

Survived 0 of 3
Foresight: complete playing field
Level 38 ptsTurn 17 / 20

Points per level

LevelGPT-6.1 TerraNemotron 3 Ultra
Level 1Second Thoughts
21 ptsSurvived
4 ptsOut of lives
Level 2Pressure Pot
9 ptsOut of lives
4 ptsOut of lives
Level 3Hide or Flight
15 ptsSurvived
8 ptsOut of lives

Cooperative planning and learning from experience. Coordinate two robots to push numbered cores onto matching sockets. Pressure plates hold doors open; moving either robot uses one turn. 5 levels in sequence, up to 152 turns in total. Earlier moves and outcomes carry forward, testing learning across levels.

GPT-6.1 Terra 77.7/100Rank 12/51

Cleared 5 of 5
Latch: complete playing field
Level 520.6 ptsTurn 27 / 40

Nemotron 3 Ultra 5.0/100Rank 45/514 of 5 levels

4 of 5 played
Latch: complete playing field
Level 413.8 ptsTurn 21 / 40

Points per level

LevelGPT-6.1 TerraNemotron 3 Ultra
Level 1Hold the door
5.2 ptsCleared
5.2 ptsCleared
Level 2Crossfeed
9.8 ptsCleared
3.2 ptsFinished early
Level 3Relay vault
19.2 ptsCleared
7.4 ptsFinished early
Level 4Passing bay
17.8 ptsClearedFinished early · 3 beacons left
13.8 ptsFinished early
Level 5Second thoughts
20.6 ptsCleared
Not played

Newton's Mirror

Same task instructions

Physics, perspective and recursive reflections, tested together. Explore the test ↗

The judgment

GPT-6.1 Terra

The sphere, airborne black and first reflected silhouettes preserve important geometry within the portrait frame. Paint deformation, contact order and forward transport are supported, with a small crimson endpoint overshoot. Major optical omissions dominate: short finite reflection sequences and smooth bands replace extensive, spatially ordered mirror imagery. Dark gloss and crisp upper emitter shapes provide partial material credit.

Nemotron 3 Ultra

The candidate establishes a separate airborne black blob and partial crimson overlap, but leaves the paint interaction history and settled support unresolved. Its main silhouette, black placement and lamp projection depart substantially from the required camera geometry. A few faint reflection hints provide little support for the extensive mirror system, while the compact paint volumes are visibly disproportionate.

Score breakdown

CategoryGPT-6.1 TerraNemotron 3 Ultra
State at 600 ms23.0/252.0/25
Camera and placement11.0/153.5/15
Reflections33.0/1204.5/120
Materials and scale7.5/103.0/10
Floor-damage reward0.0/100.0/10

Benchmark task

A spinning metal sphere and paint in a mirrored room test physical reasoning, perspective and consistency across repeated reflections.

Selfie

Different task instructions

Visual construction and creative interpretation.

The judgment

GPT-6.1 Terra

A balanced serpent emblem with six attached outward heads, delicate scales and softly rounded bodies. Its compact silhouette reads clearly, but central routing does not establish every alternating crossing or crisp inward corner. Repetitive texture, limited facial anatomy and weak contact shadows constrain its organic character.

Nemotron 3 Ultra

An endearing mechanical creature is clearly framed, with expressive amber eyes and readable segmented arms. The shell resembles layered green plates more than a deep coiled spiral. Detached-looking construction, absent working contacts and patchy rendering leave the central assembly action substantially unresolved.

Score breakdown

CategoryGPT-6.1 TerraNemotron 3 Ultra
Task & likeness7.5/104.0/10
Anatomy & construction6.5/104.0/10
Space & placement6.5/105.5/10
Light & reflections6.0/105.0/10
Purposeful detail6.5/104.0/10
Artistry & character6.5/103.0/10
Materials & effects6.0/104.0/10
Visual integrity6.0/104.5/10

Benchmark task

GPT-6.1 Terra

A pale serpent woven into an interlocking knot tests connected anatomy, repeated structure and readable overlaps. Organic surface detail must work with the overall geometry.

Nemotron 3 Ultra

A hovering mechanical nautilus tests spiral construction, connected mechanical forms and contrasting metal and illuminated surfaces.

Mona Lisa

Different task instructions

Precise visual recall and portrait reconstruction.

The judgment

GPT-6.1 Terra

A recognizable interpretation with developed facial shading, shaped sleeve folds and purposeful small features. These strengths support modest upward calibration, while the frontal torso, elongated proportions, schematic finger joints and unresolved seated support keep replication and construction uneven.

Nemotron 3 Ultra

The centered silhouette provides basic organization, but multicolored mottling and geometric overlays leave the portrait unresolved. No readable face, crossed hands, clothing or landscape establishes Mona Lisa replication. Texture and transparency offer limited visual effects without coherent anatomy, lighting or material distinctions.

Score breakdown

CategoryGPT-6.1 TerraNemotron 3 Ultra
Task & likeness5.5/100.5/10
Anatomy & construction6.5/100.0/10
Space & placement4.5/101.0/10
Light & reflections6.5/100.5/10
Purposeful detail6.0/100.5/10
Artistry & character6.0/101.5/10
Materials & effects6.0/100.0/10
Visual integrity6.5/100.5/10

Benchmark task

An SVG interpretation of the Mona Lisa tests facial likeness, anatomy and the composition of a familiar portrait.

Beach

Same task instructions

Creativity, perspective and visual beauty.

The judgment

GPT-6.1 Terra

A coherent sunset illustration with clear prompt fulfillment, controlled framing and varied, purposeful small details. Simplified joints, frontal staging, flattened animal forms and weakly directional shadows limit its anatomical, spatial and physical sophistication.

Nemotron 3 Ultra

A recognizable beach illustration with appealing warm-cool contrast, readable layers and mostly clean shapes. Unresolved seat construction, schematic animals and broad geometric foliage give it an elementary finish. Weakly coordinated reflections and limited material differentiation further constrain depth and atmosphere.

Score breakdown

CategoryGPT-6.1 TerraNemotron 3 Ultra
Task & likeness8.5/106.5/10
Anatomy & construction7.5/103.0/10
Space & placement6.5/105.0/10
Light & reflections5.5/101.5/10
Purposeful detail7.5/104.5/10
Artistry & character7.0/103.0/10
Materials & effects6.5/102.5/10
Visual integrity7.5/106.5/10

Benchmark task

A busy shoreline at sunset tests scene composition, animal forms and the relationship between light and water reflections.

Ground Truth

Same task instructions

Physical reasoning, light and visual reconstruction.

The judgment

GPT-6.1 Terra

This benchmark has not been assessed yet.

Nemotron 3 Ultra

This benchmark has not been assessed yet.

Benchmark task

A plank, computer mouse and blueberry in a steel room test physical stability, spatial relationships, materials and lighting.

Raccoon

Same task instructions

Scene composition and interacting subjects.

The judgment

GPT-6.1 Terra

A coherent cartoon with expressive animals, readable steering and a clear wake. Fine facial and hull details reward inspection. The main limits are the boatlike craft, simplified joints, weakly braced frontal raccoon and minimal directional lighting or material depth.

Nemotron 3 Ultra

The masked raccoon, dog and orange craft make the scene recognizable, with an appealing sunset palette. Overlapping bodies obscure the riding relationship, and the dog's connection to the controls remains unresolved. Weak water displacement, inconsistent shading and visible shape artifacts limit the finish. Ambiguous attachments do not establish detached limbs or inverted anatomy.

Score breakdown

CategoryGPT-6.1 TerraNemotron 3 Ultra
Task & likeness6.5/103.5/10
Anatomy & construction5.5/101.5/10
Space & placement6.0/104.5/10
Light & reflections5.0/102.0/10
Purposeful detail7.0/103.5/10
Artistry & character6.0/101.5/10
Materials & effects6.0/103.0/10
Visual integrity7.0/102.0/10

Benchmark task

A jet-ski scene pairs a canine driver with a raccoon passenger. It tests the placement and contact of interacting subjects, along with vehicle construction.

Pelican

Same task instructions

Subject construction and spatial relationships.

The judgment

GPT-6.1 Terra

A coherent pelican cyclist with expressive proportions, purposeful feather detail and developed bicycle machinery. Continuous body contours, aligned wheels and readable pedal contacts support the scene. Simplified articulation, shallow modelling and an unresolved steering connection limit construction and placement.

Nemotron 3 Ultra

A recognizable, playful pelican dominates a readable bicycle scene. Its bill and silhouette succeed, but feet below the pedals and confused drivetrain connections weaken the riding action. Local material modeling adds interest; overlapping contours, repetitive detail and inconsistent shadows leave the illustration basic and uneven.

Score breakdown

CategoryGPT-6.1 TerraNemotron 3 Ultra
Task & likeness7.0/104.0/10
Anatomy & construction7.0/103.5/10
Space & placement6.0/103.5/10
Light & reflections5.5/104.0/10
Purposeful detail7.0/105.5/10
Artistry & character6.5/104.0/10
Materials & effects5.5/106.0/10
Visual integrity6.0/103.0/10

Benchmark task

A cycling pelican tests anatomy, riding posture and contact between the bird and the bicycle.