STEALTHMARK · HEAD TO HEAD

All comparisons ↗

Muse Spark Open vs Nemotron 3 Ultra

Muse Spark Open leads Nemotron 3 Ultra by 27.4 points on StealthMark, 44.1 to 16.7. It leads on all 9 benchmarks. Muse Spark Open scores higher on Ground Truth.

See the difference ↘
All results ↗
All results ↗

Overall StealthMark

44.1/100Overall rank 29/53
16.7/100Overall rank 49/53

General Intelligence

42.6/100
12.2/100

Visual Intelligence

46.6/100
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

  • Muse Spark Open

Open or local

BENCHMARK BY BENCHMARK

Where each model leads

  • Muse Spark Open
  • Nemotron 3 Ultra
  • Other models
  • Median

DATASHEET

Specs and pricing

Muse Spark Open scores higher on StealthMark and runs 2.6× faster in our speed test. Nemotron 3 Ultra is 1.8× cheaper per output token. Both take about 1M tokens of context.

  • Muse Spark Open
  • Nemotron 3 Ultra
  • Other models
  • Median
PricePer 1M output tokens, input below
Muse Spark Open: $4.25$1.25 inputNemotron 3 Ultra: $2.401.8× cheaper$0.60 input
Context windowTokens per request, max output below
Muse Spark Open: 1MTied1M max outputNemotron 3 Ultra: 1MTied
Output speedTokens per second, our measurement
Muse Spark Open: 3612.6× fastertokens/sNemotron 3 Ultra: 139tokens/s
SizeTotal and active parameters
Muse Spark Open: 816B42B activeNemotron 3 Ultra: 550B55B active
Developer
MetaNVIDIA
Released
15 Oct 20264 Jun 2026
Origin
United StatesBoth
Input → output
Text, image, audio, video → textText → text
Architecture
Sparse mixture-of-experts Transformer with perception encoders; 62 decoder layers, 256 experts with 8 selected per token, grouped-query attention and sliding-window/full-attention layers.LatentMoE: Mamba-2 + MoE + Attention hybrid with Multi-Token Prediction

Full datasheets, every price and sourceMuse Spark Open ↗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.

Muse Spark Open 29.4/100Rank 34/47

Survived 0 of 3
Foresight: complete playing field
Level 38 ptsTurn 15 / 20

Nemotron 3 Ultra 16.9/100Rank 41/47

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

Points per level

LevelMuse Spark OpenNemotron 3 Ultra
Level 1Second Thoughts
4 ptsOut of lives
4 ptsOut of lives
Level 2Pressure Pot
9 ptsOut of lives
4 ptsOut of lives
Level 3Hide or Flight
8 ptsOut of lives
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.

Muse Spark Open 75.7/100Rank 12/48

Cleared 5 of 5
Latch: complete playing field
Level 519.6 ptsTurn 32 / 40

Nemotron 3 Ultra 5.0/100Rank 42/484 of 5 levels

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

Points per level

LevelMuse Spark OpenNemotron 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 · 1 beacon left
13.8 ptsFinished early
Level 5Second thoughts
19.6 ptsCleared
Not played

Newton's Mirror

Same task instructions

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

The judgment

Muse Spark Open

The airborne black blob and deformed paint support the broad contact sequence, although cyan attachment and wheel-directed transport remain partial. The sphere and black blob have substantial framing errors. The dominant limitation is the largely absent mirror system: faint wall circles and isolated highlights provide little evidence of recursive room geometry or curved nested reflections. Oversized compact paint features and diffuse material treatment further limit 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

CategoryMuse Spark OpenNemotron 3 Ultra
State at 600 ms14.0/252.0/25
Camera and placement6.0/153.5/15
Reflections8.0/1204.5/120
Materials and scale3.5/103.0/10
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

Muse Spark Open

The rounded silhouette and asymmetric expression make an appealing baby elephant, supported by a quiet background and grounding shadow. The protective action remains difficult to read: forefeet cannot be confidently traced into a grip, and seed contact is crowded by fine lines. Controlled simple shapes provide charm, but limited anatomical clarity, shading and surface detail leave the execution uneven.

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

CategoryMuse Spark OpenNemotron 3 Ultra
Task & likeness5.0/104.0/10
Anatomy & construction4.5/104.0/10
Space & placement6.0/105.5/10
Light & reflections5.0/105.0/10
Purposeful detail6.0/104.0/10
Artistry & character5.0/103.0/10
Materials & effects5.0/104.0/10
Visual integrity6.5/104.5/10

Benchmark task

Muse Spark Open

A small elephant protecting a delicate seed tests expressive anatomy, physical contact and contrasting organic materials.

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

Muse Spark Open

A recognizable, orderly interpretation with clean major contours, connected body forms and modest facial shading. Wide eyes, frontal symmetry and schematic hands limit likeness and expression. Layered scenery establishes basic depth, but shallow arm overlaps, flat clothing and sparse fine detail keep the execution basic and 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

CategoryMuse Spark OpenNemotron 3 Ultra
Task & likeness3.0/100.5/10
Anatomy & construction3.0/100.0/10
Space & placement5.0/101.0/10
Light & reflections4.5/100.5/10
Purposeful detail4.0/100.5/10
Artistry & character3.0/101.5/10
Materials & effects4.0/100.0/10
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

Different task instructions

Creativity, perspective and visual beauty.

The judgment

Muse Spark Open

A coherent sunset beach with readable activities, balanced framing and controlled colour transitions. Small accessories add interest, but schematic anatomy, limited surface detail, weak directional shadows and a geometric reflection constrain its finish. Most shapes and overlaps remain clean.

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

CategoryMuse Spark OpenNemotron 3 Ultra
Task & likeness8.0/106.5/10
Anatomy & construction6.0/103.0/10
Space & placement6.5/105.0/10
Light & reflections5.5/101.5/10
Purposeful detail6.5/104.5/10
Artistry & character5.5/103.0/10
Materials & effects6.0/102.5/10
Visual integrity8.0/106.5/10

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

Muse Spark Open

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

Different task instructions

Scene composition and interacting subjects.

The judgment

Muse Spark Open

Expressive faces, distinct accessories and clean color separation make the scene appealing and recognizable. Character detail is stronger than the functional construction: steering contact, limb overlaps and seating remain ambiguous. The readable hull and lively spray establish motion, while limited directional shading and simplified surfaces constrain depth and physical coherence.

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

CategoryMuse Spark OpenNemotron 3 Ultra
Task & likeness4.0/103.5/10
Anatomy & construction3.0/101.5/10
Space & placement6.0/104.5/10
Light & reflections4.5/102.0/10
Purposeful detail7.0/103.5/10
Artistry & character3.5/101.5/10
Materials & effects5.0/103.0/10
Visual integrity5.0/102.0/10

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

Different task instructions

Subject construction and spatial relationships.

The judgment

Muse Spark Open

A controlled, appealing cartoon with a recognizable pelican, expressive face and clean curved forms. Feather lines, spokes and bill shading provide useful complexity. Aligned wheels and a ground shadow establish placement, but uncertain pedal contacts and obscured mechanical connections weaken support and riding action. Lighting remains loosely coordinated with the sun.

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

CategoryMuse Spark OpenNemotron 3 Ultra
Task & likeness7.5/104.0/10
Anatomy & construction5.0/103.5/10
Space & placement6.0/103.5/10
Light & reflections5.0/104.0/10
Purposeful detail6.5/105.5/10
Artistry & character5.5/104.0/10
Materials & effects6.0/106.0/10
Visual integrity7.5/103.0/10

Benchmark task

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