Qwen3.5 27B vs 35B: In-Depth Local Performance Comparison

I put the Qwen3.5 35B A3B and the Qwen3.5 27B dense model on the same prompts, same environment, and the same sampling settings to see how they actually differ on local hardware. Both models now include vision and were tested in LM Studio on a DGX Spark with Q8 quantization, with Unsloth AI’s suggested sampling parameters for coding vs general tasks applied where relevant.

The 35B A3B runs far faster thanks to 3 billion active parameters, while the 27B dense trades speed for more consistent logical completeness in some interactive tasks. For broader model context, see our AI lineup.

Item	Qwen3.5 35B A3B	Qwen3.5 27B Dense
Architecture	Hybrid	Dense
Active parameters	3B	27B
Vision capability	Yes	Yes
Quant tested	Q8 (LM Studio Community Quant)	Q8 (Unsloth Quant, then LM Studio Community Quant)
Tokens per second	~46 t/s	~7.5 t/s OS test, ~7.2 t/s portfolio
Browser OS result	Clean UI, correct local time, 5+ apps, resizable windows	Nexus OS, no right click, resizable, start button UI is rougher
Start menu	Present and usable	Present, looks better in Retro 95 mode
Right click	Not implemented	Not implemented
Window controls	Cannot minimize or fullscreen	Resizing works; other controls varied by theme
Close button behavior	Bug closes menu bar overlay instead of window	Standard behavior in Retro 95 mode appeared fine
Terminal commands	help, date, reboot, clear all working	Not tested in this run
Games	Snake failed to run, Clicker Sim worked	Snake ran with imperfect logic, Clicker Tycoon worked
Special feature	Glitch mode toggle (visual artifacts)	Chrono Shift engine with Retro 95 theme switcher
Portfolio test (first pass)	Better than prior 122B test, solid adherence to wireframe	Stronger architectural choices, hover effects, correct name parsing
Portfolio iteration	Clear self-critique, noticeably improved second iteration	N/A in this run
Flight sim (first try)	Not covered in this run	Fully functional on first try with clouds and Sky Ace
Notes	Much faster and cleaner UI	Slower, but often more functionally complete on interactive tasks

Qwen3.5 27B vs 35B: In-Depth Local Performance Comparison

These two models sit close in footprint on disk with a big asterisk for the hybrid architecture of the 35B. The 35B A3B’s 3B active parameters give it a speed advantage, while the dense 27B keeps the full parameter set active at all times.

Both models can handle vision inputs natively, replacing the need for a separate VLM family. For a broader Qwen context, see Qwen vs GLM.

What is Qwen3.5 35B A3B?

This is a 35 billion parameter hybrid model with 3 billion active parameters. It supports longer contexts with a smaller VRAM footprint than prior non-hybrid architectures. I tested a Q8 LM Studio Community Quant and leaned on Unsloth’s suggested sampling parameters for coding vs general prompts.

What is Qwen3.5 27B Dense?

This is a 27 billion parameter dense model in the same family, with vision included. It was initially tested with an Unsloth Quant at Q8 and then swapped to the LM Studio Community Quant after I saw a community flag about an MXFP4 precision entry being present in a Q4 KXL quant for a 35B OE variant. I did not observe that specific issue on the 27B dense in my browser OS run, but I switched quant sources for safety.

Browser OS Test

I used a browser OS test v2 prompt that requires five applications, two games, wallpaper switching, and a self-chosen special feature. Both were run at Q8 on the DGX Spark in LM Studio. The speed gap was large and clearly visible.

35B A3B - Results and Behavior

It returned a complete result at roughly 46 tokens per second. The OS showed the correct local time, had at least five applications, and a working start menu. Windows were resizable but could not minimize or fullscreen.

The close button closed the menu bar overlay instead of the window itself. The terminal worked correctly with help, date, reboot, and clear. The snake game failed, but Clicker Sim ran and allowed buying an auto clicker to increase power per click.

The wallpaper options worked, and the special feature was a system instability glitch mode. The glitch mode produced heavy visual artifacts, which matched the disclaimer. The overall UI looked clean, though the close button behavior was odd.

27B Dense - Results and Behavior

This run finished at about 7.5 tokens per second, which was slower than expected. It produced Nexus OS with a clock and a start button that looked worse than the 35B version until switching themes. There was no right click, and the sampling parameters matched the coding profile used on the other model.

The calculator handled a compound expression correctly. Settings allowed wallpaper switching across multiple styles, including an Apple-like set. A Chrono Shift engine toggled between modern glass and Retro 95, and the Retro 95 start menu looked better.

Windows were resizable, icons switched to a more era-appropriate font, and the overall feature was more interesting than a glitch toggle. The retro snake game ran, though the hit detection was imperfect. Clicker Tycoon included currency and worked as intended, though the UI looked rougher than the 35B output.

Wireframe Portfolio Test

I used a Stevie Slappice portfolio wireframe and asked each model to turn it into a modern tech portfolio site. The 35B moved quickly, while the 27B delivered at around 7.2 tokens per second with Q8.

35B A3B - First Pass and Iteration

The first pass adhered well to the wireframe with fitting contact details. It surpassed my prior 122B run from earlier testing and felt more polished out of the gate. I then gave it feedback, and it generated its own critique, calling out layout rigidity and a lack of wow factor.

The second iteration added pop and improved visual impact while keeping the same photo and structure. I liked the S_L lapis underscore styling and the green accent choices. Overall, it was a clear improvement without breaking the layout.

Read More: model showdown

27B Dense - First Pass

It returned a site that placed the profile image inside a circle with a glowing border. It appeared to interpret the theme creatively while still respecting the wireframe intent and included hover effects. It parsed “Stevie” correctly and made some stronger architectural choices.

Compared one to one, the 27B result often felt more structurally thoughtful, even if the 35B’s hero section looked flashier. The 27B did not do a second iteration in this run. The speed gap was again very noticeable.

Read More: Opus compare

Flight Combat Simulator Test

I started with the 27B dense model because it takes longer to finish complex tasks. It produced a fully functional flight combat simulator on the first try at Q8 with clouds and Sky Ace. I could fly past the map bounds, which indicates the need for boundary checks.

I saw strong flight logic and working controls from a cold start. This is well done for a 27 billion parameter model and the flight logic actually works. The 35B A3B version of this specific test was not covered in this run.

Read More: Atlas vs Comet

Features Breakdown - Qwen3.5 35B A3B

• Hybrid architecture with 3B active parameters for much faster sampling.

• Built-in vision removes the need for a separate VLM.

• Strong iteration behavior in web UI tasks with self-critique and visible improvements.

• Clean UI output in the browser OS test with resizable windows.

• Working terminal with help, date, reboot, and clear.

• Glitch mode special feature for visual experimentation.

Features Breakdown - Qwen3.5 27B Dense

• Dense architecture that kept logic cohesive in several interactive tasks.

• Vision support in the same family, tested at Q8 across both Unsloth and LM Studio quants.

• Produced a fully functional flight sim on the first try.

• Browser OS special feature added a full Retro 95 theme switcher.

• Snake game ran with imperfect boundary logic, and Clicker Tycoon worked.

• Portfolio output showed thoughtful page architecture and hover effects.

Read More: Qwen vs GLM

Pros and Cons - Qwen3.5 35B A3B

Pros:

• Much faster token generation at Q8.
• Clean UI and stronger polish on first passes.
• Excellent iterative refinement with self-critique.

Cons:

• Snake game did not run in the browser OS test.
• Close button bug closed the menu bar overlay.
• Special feature was less useful than a theme engine.

Pros and Cons - Qwen3.5 27B Dense

Pros:

• Produced a working flight sim on the first try.
• Retro 95 theme switching was a cooler special feature.
• Snake game ran and portfolio architecture felt solid.

Cons:

• Much slower at Q8 on the same hardware.
• Some UI elements looked rough out of the box.
• Snake logic and some controls needed refinement.

Use Cases - Qwen3.5 35B A3B

• Local users who prioritize speed and quick iteration cycles.
• Rapid prototyping of UI-heavy web tasks with iterative polish.
• Mixed vision and text prompts where throughput matters.

Use Cases - Qwen3.5 27B Dense

• Local builds where functional completeness of interactive logic is prioritized.
• Themed UI work that benefits from coherent styling systems.
• Complex coding tasks that can afford slower sampling for better fidelity.

Read More: model showdown

Final Conclusion

The 35B A3B is the speed pick and produced cleaner UI with excellent iterative improvements on the portfolio test. The 27B dense is slow but hit functional wins like a working snake game and a first-try flight sim, plus a more interesting OS theme feature.

Pick the 35B A3B if you need fast local inference with strong polish and iteration. Pick the 27B dense if you value functional completeness on interactive tasks and can accept slower speeds. If you want a broad view of adjacent options, scan our AI lineup as well.