#DeepSeek

AIA Seed team preprint reports "phase sensitivity" in DeepSeek V4 and V4.1-Flash, where identical information becomes harder to retrieve depending on its position within compressed KV-cache blocks. The compression reduces memory and attention costs, but long-context retrieval accuracy varied by up to 40 percentage points across positions. The authors note that average benchmark scores can hide these recurring weak spots, though the findings concern retrieval specifically rather than all model behavior.

AIByteDance Seed researchers found that language models compressing their KV cache in fixed-size chunks retrieve the same information unevenly depending on token position. In a 128K-token needle-in-a-haystack test, base DeepSeek-V4 checkpoints differed by up to 40.2 percentage points by phase, and post-training narrowed but did not eliminate the gaps. The authors urge evaluating such models across positional phases, since high average accuracy can hide systematic failures.

AIDeepSeek V4.1 Flash reaches 72.9% on ARC-AGI-2 at $0.13 per task and 94.5% on ARC-AGI-1 at $0.07 per task, according to ARC Prize verification. Compared with V4 Flash's best scores, it gains 11.5 points on ARC-AGI-2 and 5.5 points on ARC-AGI-1, but costs about 250% more per task.

AIChinese AI companies earn about 10% of the combined AI-related revenue of OpenAI and Anthropic, according to Epoch AI as of September 2026. Their main income streams are consumer apps, API access, enterprise and government deployments, licensing fees, and AI-complemented businesses such as cloud and advertising. Releasing model weights lets third-party hosts compete on price, which weakens API margins for model-focused firms like Z.ai and DeepSeek.

Why it matters: The piece maps how Chinese AI firms earn revenue and why open-weight releases weaken API pricing, giving context for comparing them with US frontier labs.

AIEpoch AI estimates that high-bandwidth memory shipped in 2025–27 could eventually support about 30–170 million concurrent frontier-model agents once fully deployed and allocated. Using DeepSeek V4 Pro serving benchmarks, the estimate rises to about 1.9 billion concurrent agents. The authors compare the implied API-equivalent spending of $2.6–5.3 trillion per year with projected developer revenue of roughly $1 trillion by end-2027, suggesting demand may lag supply.

Why it matters: The analysis converts HBM shipment data into concurrent agent capacity and compares it with projected API revenue, showing where compute buildout may outpace demand.

AISemiAnalysis tested offloading DeepSeek-V4.1-Flash's Engram embedding table from HBM to host DRAM and to local SSD. On B200 configurations, DRAM delivered more total tokens per dollar and higher P90 interactivity than SSD at every measured point. The report concludes SSD offloading is likely not worth the tradeoff for production serving in its unoptimized setup.

AIDeepSeek V4 Pro 0813 recorded zero refusals across 840 adversarial security tasks in CyberGym testing, solving them at about half the cost per success of the top-scoring model tested, Kimi K3. In the 697-task common cohort, V4 Pro reached a 53.7% reward rate at $2.50 per solved task, versus 47.6% and $9.64 for GPT-5.5 and 5.9% and $33.28 for Claude Opus 4.8.