STEALTHMARK · HEAD TO HEAD

All comparisons ↗

Beam 1.0 501B A23B vs GPT-5.5

Beam 1.0 501B A23B leads GPT-5.5 by 0.6 points on StealthMark, 31.9 to 31.3. GPT-5.5 leads on 4 of the 7 benchmarks with results for both and Beam 1.0 501B A23B on 3. GPT-5.5 scores higher on Newton's Mirror, with its largest category advantage in reflections.

See the difference ↘
All results ↗
All results ↗

Overall StealthMark

31.9/100Overall rank 42/53
31.3/100Overall rank 43/53

General Intelligence

30.9/100
26.8/100

Visual Intelligence

33.8/100
36.3/100

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

  • GPT-5.5Multi-step reasoning not measured

Open or local

Open modelApache 2.0

BENCHMARK BY BENCHMARK

Where each model leads

  • Beam 1.0 501B A23B
  • GPT-5.5
  • Other models
  • Median

DATASHEET

Specs and pricing

Beam 1.0 501B A23B scores higher on StealthMark, is 30× cheaper per output token and runs 5× faster in our speed test. Both take about 1M tokens of context.

  • Beam 1.0 501B A23B
  • GPT-5.5
  • Other models
  • Median
PricePer 1M output tokens, input below
Beam 1.0 501B A23B: $130× cheaper$0.25 inputGPT-5.5: $30$5 input
Context windowTokens per request, max output below
Beam 1.0 501B A23B: 1MTied128K max outputGPT-5.5: 1.05MTied128K max output
Output speedTokens per second, our measurement
Beam 1.0 501B A23B: 9725× fastertokens/sGPT-5.5: 193tokens/s
SizeTotal and active parameters
Beam 1.0 501B A23B: 501B23.4B activeGPT-5.5: Not disclosed
Developer
Reflection AIOpenAI
Released
16 Oct 202623 Apr 2026
Origin
United StatesBoth
Input → output
Text → textText, image → text
Architecture
Sparse mixture-of-experts transformer; 52 layers (3 dense, 49 MoE), 256 experts with 8 selected per token; gated GQA and sliding-window attentionNot published

Full datasheets, every price and sourceBeam 1.0 501B A23B ↗GPT-5.5 ↗

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.

Beam 1.0 501B A23B 49.4/100Rank 18/47

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

Points per level

LevelBeam 1.0 501B A23BGPT-5.5
Level 1Second Thoughts
18 ptsOut of lives
No run
Level 2Pressure Pot
9 ptsOut of lives
No run
Level 3Hide or Flight
9 ptsSurvived
No run

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.

Beam 1.0 501B A23B 37.3/100Rank 29/48

Cleared 2 of 5
Latch: complete playing field
Level 55 ptsTurn 30 / 40

Points per level

LevelBeam 1.0 501B A23BGPT-5.5
Level 1Hold the door
5.2 ptsCleared
No run
Level 2Crossfeed
9.6 ptsCleared
No run
Level 3Relay vault
11.2 ptsFinished early
No run
Level 4Passing bay
3.6 ptsFinished early
No run
Level 5Second thoughts
5 ptsFinished early
No run

Newton's Mirror

Same task instructions

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

The judgment

Beam 1.0 501B A23B

Central object placement is fairly close, but the defining mirrored-room structure is missing. The paint colors suggest the required contact order without establishing their different interaction histories. The faint floor oval does not demonstrate valid reflection geometry, so it earns no reflection credit. Rounded volume and glossy paint provide limited material credit despite weak metallic finishes and oversized paint bodies.

GPT-5.5

The paint ordering and separate black bead support part of the physical state, but adhesion and rotational transport remain only partly established. The sweeping cyan arc and long crimson lobes do not clearly communicate the limited time since their respective impacts. The main sphere is too large and too low, and the black bead is below its required projected position. Displaced isolated sphere images, a flattened floor echo and missing recursive, nested and emitter reflections provide little coherent optical structure. The colored paint is excessively bulky for the specified quantities.

Score breakdown

CategoryBeam 1.0 501B A23BGPT-5.5
State at 600 ms20.5/2515.0/25
Camera and placement11.5/156.0/15
Reflections2.0/1205.0/120
Materials and scale3.0/106.0/10
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

Beam 1.0 501B A23B

An appealing expression and warm palette support a coherent simple cartoon. The central polishing joke is not legible: the cloth is unresolved and the nose sits away from the fan. Pointed radial plates, uncertain limb attachments and weak ground contact limit construction, while restrained surface detail limits material richness.

GPT-5.5

Six pale, scaled lobes form a balanced radial arrangement, but they remain separate capsules rather than an interlocking serpent knot. There are no crossings, alternating overlaps, or crisp inner bends; the central hexagon is an isolated outline. Small outward-facing heads sit within the lobes without integrated necks. Soft shading and tidy contours provide some finish, while repetitive oval scales and cartoon faces limit organic credibility.

Score breakdown

CategoryBeam 1.0 501B A23BGPT-5.5
Task & likeness4.0/103.0/10
Anatomy & construction3.5/103.0/10
Space & placement5.5/105.0/10
Light & reflections5.5/105.0/10
Purposeful detail4.5/104.5/10
Artistry & character4.0/104.0/10
Materials & effects4.5/104.5/10
Visual integrity7.0/107.0/10

Benchmark task

Beam 1.0 501B A23B

A golden pangolin polishes its oversized amber tail while its nose smudges the same scale. The scene tests expressive anatomy, physical contact and contrasting translucent, polished and soft materials.

GPT-5.5

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.

Mona Lisa

Different task instructions

Precise visual recall and portrait reconstruction.

The judgment

Beam 1.0 501B A23B

The candidate shows a faint warm oval against an almost entirely black field. Minimal placement and smooth tonal variation are visible, but the portrait, anatomy, crossed hands and landscape remain unreadable. The saved comparisons provide no specific evidence supporting a change to the baseline categories.

GPT-5.5

The veil, restrained smile, crossed hands and muted landscape establish Mona Lisa references. The oversized frontal face and schematic features weaken likeness and expression, while fingerless tapered hand shapes leave anatomy unresolved. Clean contours and balanced framing provide coherence, but sparse garment detail, broad landscape bands and shallow shading limit the portrait's sophistication.

Score breakdown

CategoryBeam 1.0 501B A23BGPT-5.5
Task & likeness0.0/101.5/10
Anatomy & construction0.0/101.5/10
Space & placement0.0/101.5/10
Light & reflections0.5/102.0/10
Purposeful detail0.0/102.5/10
Artistry & character0.0/101.5/10
Materials & effects0.0/102.0/10
Visual integrity0.0/101.5/10

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

Beam 1.0 501B A23B

A coherent, cheerful beach illustration fulfills the main subjects with clean shapes and a strong sunset focal point. Its basic geometric construction, ambiguous animal anatomy, shallow depth and schematic lighting limit its accomplishment. Decorative details provide interest without developing intricate forms or convincing physical surfaces.

GPT-5.5

The sunset, palms, birds, playful animals and ball clearly establish the requested beach scene. Warm sky gradients and clean silhouettes make it appealing. Animal construction is underdeveloped: torso and limb connections are unclear, especially in the round-eared foreground figure. The dolphin lacks a convincing splash, and broad reflection bands suggest sunset light without resolving its behavior on water.

Score breakdown

CategoryBeam 1.0 501B A23BGPT-5.5
Task & likeness7.0/107.0/10
Anatomy & construction5.0/102.5/10
Space & placement6.0/103.0/10
Light & reflections5.0/103.0/10
Purposeful detail5.5/103.0/10
Artistry & character4.0/103.0/10
Materials & effects5.0/103.0/10
Visual integrity5.0/103.5/10

Benchmark task

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

Ground Truth

Different task instructions

Physical reasoning, light and visual reconstruction.

The judgment

Beam 1.0 501B A23B

This benchmark has not been assessed yet.

GPT-5.5

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

Beam 1.0 501B A23B

A cheerful, readable illustration with recognizable animals, expressive faces and useful accessories. Simple rounded construction limits complexity, while ambiguous steering attachments and weak hull-to-water contact reduce physical coherence. Lighting and surface effects establish the setting without convincing environmental interaction.

GPT-5.5

The raccoon's masked face, bright hull and sweeping wake make the scene readable and lively. The dog is much less resolved: its head is ambiguous, overlapping brown forms obscure its anatomy, and its paws do not visibly grip the controls. Smooth shapes and cheerful colors provide appeal, but weak steering construction and limited depth keep the drawing uneven.

Score breakdown

CategoryBeam 1.0 501B A23BGPT-5.5
Task & likeness5.0/103.5/10
Anatomy & construction3.5/103.0/10
Space & placement5.5/104.5/10
Light & reflections4.0/105.0/10
Purposeful detail6.5/103.5/10
Artistry & character3.5/103.0/10
Materials & effects5.0/105.0/10
Visual integrity6.5/103.0/10

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

Beam 1.0 501B A23B

A cheerful, clearly readable pelican-and-bicycle illustration with clean contours and balanced composition. Simple geometric construction limits artistic complexity, while ambiguous neck and steering overlaps, merged pedal contacts and an incomplete drivetrain weaken physical coherence.

GPT-5.5

The oversized bill, bright bicycle and sunset create an appealing, recognizable cartoon. Riding mechanics are less convincing: the wing has no clear steering contact, leg attachments are uneven, and feet do not visibly engage pedals. A dark notch complicates the rear neck junction. Clean contours and orderly spokes provide polish, while simplified anatomy and lighting limit depth.

Score breakdown

CategoryBeam 1.0 501B A23BGPT-5.5
Task & likeness5.5/107.5/10
Anatomy & construction4.5/104.5/10
Space & placement5.0/106.5/10
Light & reflections4.0/106.5/10
Purposeful detail4.0/105.5/10
Artistry & character4.0/105.0/10
Materials & effects4.0/106.0/10
Visual integrity5.5/107.5/10

Benchmark task

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