STEALTHMARK · HEAD TO HEAD

All comparisons ↗

GPT-6.1 Terra Low vs Nemotron 3 Ultra

GPT-6.1 Terra Low leads Nemotron 3 Ultra by 24.6 points on StealthMark, 41.3 to 16.7. It leads on all 9 benchmarks. GPT-6.1 Terra Low scores higher on Newton's Mirror, with its largest category advantage in state at 600 ms.

See the difference ↘
All results ↗
All results ↗

Overall StealthMark

41.3/100Overall rank 35/55
16.7/100Overall rank 51/55

General Intelligence

34.3/100
12.2/100

Visual Intelligence

53.1/100
26.5/100

Open or local

BENCHMARK BY BENCHMARK

Where each model leads

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

DATASHEET

Specs and pricing

  • GPT-6.1 Terra Low
  • Nemotron 3 Ultra
  • Other models
  • Median
PricePer 1M output tokens, input below
GPT-6.1 Terra Low: No list priceNemotron 3 Ultra: $2.40$0.60 input
Context windowTokens per request, max output below
GPT-6.1 Terra Low: Not publishedNemotron 3 Ultra: 1M
Output speedTokens per second, our measurement
GPT-6.1 Terra Low: Not measuredNemotron 3 Ultra: 139tokens/s
SizeTotal and active parameters
GPT-6.1 Terra Low: Not disclosedNemotron 3 Ultra: 550B55B active
Developer
Not publishedNVIDIA
Released
Not published4 Jun 2026
Origin
Not publishedUnited States
Input → output
Not publishedText → text
Architecture
Not publishedLatentMoE: Mamba-2 + MoE + Attention hybrid with Multi-Token Prediction

Full datasheets, every price and sourceNemotron 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 Low 36.1/100Rank 26/51

Survived 1 of 3
Foresight: complete playing field
Level 39 ptsTurn 20 / 20

Nemotron 3 Ultra 16.9/100Rank 45/51

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

Points per level

LevelGPT-6.1 Terra LowNemotron 3 Ultra
Level 1Second Thoughts
4 ptsOut of lives
4 ptsOut of lives
Level 2Pressure Pot
8 ptsOut of lives
4 ptsOut of lives
Level 3Hide or Flight
9 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 Low 62.4/100Rank 23/52

Cleared 4 of 5
Latch: complete playing field
Level 520.6 ptsTurn 27 / 40

Nemotron 3 Ultra 5.0/100Rank 46/524 of 5 levels

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

Points per level

LevelGPT-6.1 Terra LowNemotron 3 Ultra
Level 1Hold the door
5.2 ptsCleared
5.2 ptsCleared
Level 2Crossfeed
9.2 ptsCleared
3.2 ptsFinished early
Level 3Relay vault
18.8 ptsCleared
7.4 ptsFinished early
Level 4Passing bay
10.2 ptsFinished early
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 Low

Deformed colored paint and a separate airborne black body establish readable interaction history. Cyan has travelled too far, framing differs substantially, and the mirror system supplies only elementary bands and oval copies. Missing recursive geometry, nested spherical imagery and emitter mapping remain the dominant weaknesses.

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 Terra LowNemotron 3 Ultra
State at 600 ms22.0/252.0/25
Camera and placement4.0/153.5/15
Reflections10.0/1204.5/120
Materials and scale6.0/103.0/10
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 Low

Six attached outward-facing heads, delicate scales and soft ivory shading establish an orderly decorative motif. Separate paddle-shaped bodies replace the required interlocking loops and leave no enclosed central hexagon. Surface detail provides interest, but repeated simple forms, schematic faces and limited anatomical modeling constrain the result.

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 Terra LowNemotron 3 Ultra
Task & likeness4.0/104.0/10
Anatomy & construction3.5/104.0/10
Space & placement4.5/105.5/10
Light & reflections5.5/105.0/10
Purposeful detail5.5/104.0/10
Artistry & character5.0/103.0/10
Materials & effects5.5/104.0/10
Visual integrity4.0/104.5/10

Benchmark task

GPT-6.1 Terra Low

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 Low

A recognizable, coherent portrait with purposeful facial detail, warm local volume and layered scenery. The frontal pose, enlarged face, merged hands and shallow clothing construction substantially limit replication and drawing skill. The visible successes support retaining the current assessment.

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 Terra LowNemotron 3 Ultra
Task & likeness5.0/100.5/10
Anatomy & construction4.5/100.0/10
Space & placement5.0/101.0/10
Light & reflections6.0/100.5/10
Purposeful detail5.0/100.5/10
Artistry & character5.5/101.5/10
Materials & effects5.0/100.0/10
Visual integrity6.0/100.5/10

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 Low

A coherent sunset scene demonstrates the beach, animals, birds and reflections. Flowing silhouettes, warm color transitions and intact attachments are its strongest properties. Simplified anatomy, the turtle's elevated viewing angle and symbolic surface effects constrain drawing complexity and physical depth.

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 Terra LowNemotron 3 Ultra
Task & likeness8.0/106.5/10
Anatomy & construction5.5/103.0/10
Space & placement5.5/105.0/10
Light & reflections6.5/101.5/10
Purposeful detail6.0/104.5/10
Artistry & character5.0/103.0/10
Materials & effects5.5/102.5/10
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 Low

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 Low

Recognizable animals, a coherent craft and sweeping wake make an appealing cartoon. Basic limb construction, weakly demonstrated raccoon seating and limited shared perspective constrain the scene. Small identifying details work well, while lighting and materials remain broadly graphic.

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 Terra LowNemotron 3 Ultra
Task & likeness6.5/103.5/10
Anatomy & construction5.0/101.5/10
Space & placement5.5/104.5/10
Light & reflections4.5/102.0/10
Purposeful detail6.0/103.5/10
Artistry & character5.0/101.5/10
Materials & effects5.0/103.0/10
Visual integrity6.0/102.0/10

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 Low

A coherent coastal illustration with a distinctive pelican, controlled contours and clearly organised bicycle wheels. Visible saddle support and shaped neck and wing contours earn credit beyond basic geometric construction. Rubbery legs, unresolved pedal contacts and absent steering contact limit the riding action. Lighting and materials remain restrained and spatially shallow.

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 Terra LowNemotron 3 Ultra
Task & likeness7.0/104.0/10
Anatomy & construction5.5/103.5/10
Space & placement6.0/103.5/10
Light & reflections5.5/104.0/10
Purposeful detail6.5/105.5/10
Artistry & character6.0/104.0/10
Materials & effects6.0/106.0/10
Visual integrity6.0/103.0/10

Benchmark task

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