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Gemini Executive Synthesis

TurboQuant (turbo3/turbo4 cache types) for LLM inference, specifically its compatibility with new NVIDIA Blackwell GPUs.

Technical Positioning
Achieving reliable, performant LLM inference on cutting-edge GPU architectures (NVIDIA Blackwell, compute capability 12.0) using optimized quantization schemes.
SaaS Insight & Market Implications
This issue exposes a critical compatibility gap for TurboQuant's CUDA kernels on NVIDIA's new Blackwell architecture (sm_120). The failure to produce coherent output with `turbo3`/`turbo4` cache types, while `q8_0` functions correctly, indicates a fundamental problem with dequantization kernels on this specific hardware. This is a significant market implication: early adopters of new GPU generations will face immediate performance and reliability issues with advanced quantization techniques. SaaS providers leveraging such optimizations for cost-effective LLM inference must prioritize rapid validation and adaptation to new hardware. Failure to support cutting-edge silicon directly impacts market readiness and competitive advantage, particularly as hardware cycles accelerate.
Proprietary Technical Taxonomy
turbo3 turbo4 cache-type-k cache-type-v garbled output repetitive output q8_0 CUDA dequantization kernels

Raw Developer Origin & Technical Request

Source Icon GitHub Issue Mar 31, 2026
Repo: TheTom/turboquant_plus
turbo3/turbo4 cache produces garbled output on NVIDIA Blackwell GPU (RTX 5070 Laptop, compute capability 12.0)

## Environment
- OS: CachyOS Linux (kernel 6.19.10)
- GPU: NVIDIA GeForce RTX 5070 Laptop GPU
- VRAM: 8GB (7707 MiB)
- CUDA Version: 13.2
- Driver: 595.58.03
- Compute Capability: 12.0 (Blackwell)
- Build: 8665 (5364f8a1d) with GNU 15.2.1

## Model
- qwen2.5-coder:7b-instruct-q6_K (GGUF)

## Command
llama-server
-m qwen2.5-coder-7b-q6_K.gguf
-ngl 99 -c 32768 -fa on
--cache-type-k turbo3
--cache-type-v turbo3
--host 0.0.0.0 --port 8080
## Expected behavior
Coherent text output as reported in the paper on Apple Silicon.

## Actual behavior
Garbled, repetitive output. Examples:
- Prompt: "Write a hello world in Python"
- Response: `"Here is a simple simple simple Python program that world world:\n\nprint(\"Hello world\")"`

turbo3/turbo4 on both K and V produces broken output.
K=turbo3 + V=q8_0 also produces broken output (only 3 tokens generated).
K=q8_0 + V=q8_0 works correctly.

## Notes
This appears to be the first test of TurboQuant CUDA kernels on Blackwell (sm_120).
The CUDA build succeeded without errors (ARCHS=1200).
The issue is likely in the CUDA dequantization kernels not being validated for sm_120.

Developer Debate & Comments

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Adjacent Repository Pain Points

Other highly discussed features and pain points extracted from TheTom/turboquant_plus.

Extracted Positioning
turbo3 quantization for LLM KV cache compression
Achieving 4.6x compression with quality (perplexity, KL divergence, NIAH) comparable to q8_0 (within 2% PPL) and superior to q4_0, while maintaining high inference speed.
Top Replies
TheTom • Mar 25, 2026
## CRITICAL: Perplexity test reveals quality failure | Cache | PPL | vs f16 | |-------|-----|--------| | f16 | 6.121 | baseline | | q8_0 | 6.111 | -0.16% | | q4_0 | 6.142 | +0.34% | | **turbo3** | ...
TheTom • Mar 25, 2026
## Root causes found ### 1. V cache in rotated space Python verification: dequant output has cosine=0.02 with input (garbage). After inverse rotation: cosine=0.987 (correct). V cache values MUST be...
TheTom • Mar 25, 2026
## QUALITY FIXED ✅ Perplexity with inverse rotation restored in dequant: | Cache | PPL | vs q8_0 | |-------|-----|---------| | f16 | 6.121 | — | | q8_0 | 6.111 | baseline | | q4_0 | 6.142 | +0.5% ...
Extracted Positioning
`turbo3` decode performance for LLM inference on Apple Silicon (M1, M2 Pro, M5 Max), specifically addressing the 'decode cliff' at increasing context depths.
Achieving flat, high-performance `turbo3` decode ratios (0.90x+ of `q8_0`) across all context depths on Apple Silicon, minimizing performance degradation from memory access patterns.
Top Replies
TheTom • Mar 27, 2026
## M2 Pro Results: Bit-Arithmetic Dequant **Hardware:** Apple M2 Pro, Apple8 (1008), has_tensor=false, 32GB **Model:** Qwen2.5-7B-Instruct-Q4_K_M **Build:** experiment/m1-m2-decode-comparison (auto...
TheTom • Mar 27, 2026
## M2 Pro Results Update: Batched Extract IS a Win True baseline comparison (same branch chain, same build): | Depth | q8_0 | Main (const LUT) | Batched extract | Bit-arithmetic | |-------|------|-...
TheTom • Mar 27, 2026
## BREAKTHROUGH: Profiling isolation identifies exact bottleneck Added TURBO_PROFILE_MODE (0-4) to strip away dequant layers one at a time. ### M5 Max vs M2 Pro at 8K context decode: | Mode | What ...
Extracted Positioning
TurboQuant (`-ctk turbo3 -ctv turbo3`) integration with Vulkan devices for LLM inference.
Achieving broad hardware compatibility for TurboQuant, specifically extending to Vulkan-enabled AMD GPUs.
Extracted Positioning
TurboQuant (turbo3 and turbo4) performance optimization for LLM inference, specifically on Apple M1 hardware.
Achieving superior LLM inference speed (tokens/sec) through TurboQuant optimizations on Apple Silicon (M1).
Extracted Positioning
TurboQuant's quantization strategy, specifically regarding K/V norm disparity, attention quantization methods (MSE vs. Prod), and outlier detection (dynamic vs. fixed).
Advancing TurboQuant's quantization efficacy to achieve lower perplexity (PPL) and higher compression (lower average bit rates) through refined techniques.

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Issue Status

Cross-Market Term Frequency

Quantifies the cross-market adoption of foundational terms like turbo3 and turbo4 by tracking occurrence frequency across active SaaS architectures and enterprise developer debates.