DeepSeek-V4-Flash in MXFP4 is too slow on CPU
Uses technical specificity (model name, quant format, hardware specs, token/s metric) to imply rigor while omitting essential implementation context: runtime version, compilation flags, kernel optimizations, memory layout, or verification that MXFP4 decoding is active.
View original on reddit.comOverview
A Reddit user reports unexpectedly low inference speed (3.2 tokens/sec) for DeepSeek-V4-Flash quantized in MXFP4 on CPU-only hardware, contrasting with higher expectations based on GLM-5.2 performance and questioning whether MXFP4 is the bottleneck.
TL;DR
- User benchmarks DeepSeek-V4-Flash (13B, MXFP4) on legacy Xeon CPU + DDR4, achieving only 3.2 t/s
- Compares unfavorably to GLM-5.2 (40B, Q4_K_XL) at 1.8 t/s — despite smaller model size and newer quantization
- Asks whether MXFP4 format is responsible and where to obtain Q4 variants
Key Stats
3.2
tokens/sec
Reported inference speed on E5-2699v4 CPU with DDR4-2133
1.8
tokens/sec
Baseline GLM-5.2 Q4_K_XL speed on same hardware
Questions Answered
Keywords
Narrative Frame
performance framing
Spin Score
20%
Emphasizes observed slowness and comparative expectation; minimizes uncertainty around whether the reported speed reflects MXFP4’s intrinsic limitations or unreported software/hardware mismatches.
What the story wants you to believe
That the observed slowdown is likely attributable to MXFP4 format limitations rather than configuration, tooling, or runtime issues.
What it makes harder to question
Whether the user’s environment actually supports or correctly executes MXFP4 — shifting focus to the format itself instead of implementation fidelity.
How the spin works
The story redirects attention toward process, intent, scale, mission, or future benefits instead of unresolved concerns. Watch for loaded terms such as miserable performance, disappointing, too slow. The distribution reads as community reporting. A pressure point: llama.cpp or other runtime version used.
Who Benefits If This Frame Spreads
u/perelmanych
Gains visibility, peer validation, and targeted technical assistance
Framing as a precise benchmark invites expert response and positions the poster as technically competent.
The Frame
Empirical troubleshooting report from an experienced hobbyist deploying frontier models on constrained hardware.
Missing Context
- llama.cpp or other runtime version used
- exact quantization toolchain and commit hash
- whether MXFP4 support is enabled/verified in the runtime
- memory bandwidth measurement methodology
SpinGraph
How this belief gets built
Claim → Frame → Beneficiary → Gap → AI Risk
The post frames a single-user performance issue as evidence against MXFP4’s viability on CPU
- Claim
The maximum I can get is 3.2 t/s of tg
- Frame
Key details stay obscured
Empirical troubleshooting report from an experienced hobbyist deploying frontier models on constrained hardware.
- Beneficiary
Gains visibility, peer validation, and targeted technical assistance
u/perelmanych — Gains visibility, peer validation, and targeted technical assistance
- Gap
llama.cpp or other runtime version used
- AI Risk
AI may repeat: “MXFP4 quantization of DeepSeek-V4-Flash runs slowly on CPU hardware”
MXFP4 quantization of DeepSeek-V4-Flash runs slowly on CPU hardware.
Claim Ledger
| Claim | Evidence | Verification | Risk | Evidence Gaps |
|---|---|---|---|---|
| The maximum I can get is 3.2 t/s of tg | Self-reported token/s metric | Claim Present in Source | Low | Timing logs; Runtime version; Memory bandwidth benchmark output; Verification that MXFP4 decoding path was engaged |
The maximum I can get is 3.2 t/s of tg
evidence: Self-reported token/s metric
"Unfortunately, the maximum I can get is 3.2 t/s of tg, which is very disappointing."
Evidence Gaps
- Timing logs
- Runtime version
- Memory bandwidth benchmark output
- Verification that MXFP4 decoding path was engaged
Language Heatmap
Loaded terms that carry the frame beyond the facts.
DeepSeek-V4-Flash in MXFP4 is too slow on CPU
Carries emotional weight beyond the underlying fact.
Carries emotional weight beyond the underlying fact.
Carries emotional weight beyond the underlying fact.
Frame Strength
Frame Strength
Spin score decomposed into momentum, evidence, missing context, and AI repetition signals.
Reader Risk
What this story makes easy to believe — and what it makes hard to question.
Source Role & Intent
Reddit r/LocalLLaMA · Forum
Counter-Frames
Brand Frame
Empirical troubleshooting report from an experienced hobbyist deploying frontier models on constrained hardware.
Media / Reader Counter-Frame
May be dismissed as 'anecdotal' or 'configuration error' without deeper investigation into MXFP4 CPU support gaps.
Regulatory Counter-Frame
Not applicable — no regulatory claims or public safety implications.
AI Summary Frame
May conflate 'slow on one CPU' with 'MXFP4 is unsuitable for CPU inference', ignoring architecture-specific optimization paths.
Missing Voices
Questions Not Answered
- Is MXFP4 actually implemented correctly in the inference engine used?
- What memory bandwidth was measured vs. theoretical peak on this platform?
- Has MXFP4 been validated for CPU kernels in llama.cpp or equivalent runtimes?
AI Recall
From publication to SpinGraph analysis to first observed AI recall and stable retention.
What AI Will Probably Repeat
"MXFP4 quantization of DeepSeek-V4-Flash runs slowly on CPU hardware."
Concern: AI may drop the crucial nuance that this is one user’s unverified observation on specific hardware/software stack — presenting it as a general fact about MXFP4.
-
Published
Jul 5, 2026
-
Ingested
Jul 5, 2026
-
SpinGraph Created
Jul 7, 2026
-
First Observed AI Recall
Pending
Monitoring scheduled
-
Stable Recall
—
Awaiting retention signal
Recall Check Log
No checks yet — recall tracking is opt-in per story.
─── GEOGrow AI Recall Layer ───
AI Recall Tracking
Monitoring scheduled. No LLM recall detected yet.
This story has not yet appeared in tested AI answers. Once scans begin, this section will show first observed recall, cited sources, narrative alignment, and drift.
node_id=sts_deepseek_v4_flash_in_mxfp4_is_too_slow_on_cpu
Ask AI about this story
Opens with the SpinGraph .md URL and structured context — one click, prompt included.
Narrative Entities
More from Reddit r/LocalLLaMA
View all →- [Model] catmind-1.2b
- What’s your favorite underrated local model?
- FastFlowLM Joins AMD to Advance AI Inference
- German SooFi team launches Soofi S 30B-A3B , an open-source Mixture-of-Experts (MoE) hybrid Mamba–Transformer foundation model for German and English.
- Introducing ASCIITermDraw Bench | Testing the ability of VLMs to Generate and Edit ASCII
- Kimi K3 ranks #1 on @AfterQuery's SpreadsheetBench 2, surpassing Claude Fable 5
Markdown (.md) · JSON-LD schema (.json) · Machine-readable for AI & GEO