How GraphRAG Outperforms Vector Search in Enterprise LLM Accuracy

“We replaced vector search with GraphRAG—accuracy jumped 3.4x.”

Table of Contents

Why Enterprise Queries Need More Than Vectors

In late 2023, Diffbot released the KG-LM Accuracy Benchmark, a public study evaluating how knowledge graphs impact the performance of large language models (LLMs) in enterprise scenarios. The benchmark tests how well LLMs answer 43 business-relevant questions—with and without access to a structured knowledge graph.

The research compares traditional vector search pipelines to graph-based retrieval (GraphRAG), quantifying differences in accuracy across categories like operational analytics, KPI tracking, and strategic planning. For software architects evaluating RAG techniques in enterprise stacks, this benchmark surfaces a critical insight: vector embeddings are not enough when queries depend on structure.

If you’re still running vanilla RAG on high-entity queries, you’re flying blind. Here’s what the data proves—and why forward-leaning teams are already moving to graph-native stacks.

KG-LM Accuracy Benchmark GraphRAG flowchart

Defining GraphRAG

GraphRAG uses a knowledge graph as the retrieval substrate instead of unstructured document vectors. The graph explicitly encodes entity relationships, making it easier for an LLM to retrieve schema-aligned context. This contrasts with standard vector search, which uses embedding-based similarity to retrieve context without structural alignment.

Study Objective

The benchmark compares LLM performance across 43 enterprise-specific questions in four categories:

  • Day-to-day analytics
  • Operational analytics
  • Metrics & KPIs
  • Strategic planning

The benchmark measures accuracy with and without knowledge graph integration.

Results: GraphRAG Triples Accuracy in Enterprise Settings

Overall Accuracy

  • LLM without KG grounding: 16.7%
  • LLM with KG grounding (GraphRAG): 56.2%
  • Accuracy gain: 3.4x increase

“This study shows that using a knowledge graph is not just beneficial—it’s functionally required for certain classes of enterprise questions.” — Mike Tung, CEO, Diffbot [1]

Performance Breakdown

LLM with and without knowledge graph grounding results 2023

These results confirm that vector-only systems cannot handle schema-intensive queries. Both Metrics & KPIs and Strategic Planning categories saw zero accuracy from traditional vector RAG.

Schema Dependence and Entity Density

  • Accuracy degrades to 0% as the number of entities per query increases beyond five (without KG support).
  • GraphRAG sustains stable performance even with 10+ entities per query.

This trend reinforces that surface-level similarity alone is not sufficient for high-entity-density queries.

“Graphs give structure to knowledge that language models alone can’t replicate.” — Kurt Bollacker, Data Scientist [2]

KG-LM Accuracy Benchmark types of questions

Practical Implications for Developers

When to Use GraphRAG

Use GraphRAG instead of traditional RAG when:

  • Queries involve business logic or metric definitions
  • Answers require multi-hop relationships between entities
  • Schema conformity is critical (e.g., KPIs, forecasts, system state)

Tooling and Frameworks

  • FalkorDB: A high-throughput graph database optimized for GraphRAG use cases. See FalkorDB Docs.
  • LangChain: Supports graph-based retrievers and can integrate with FalkorDB for hybrid pipelines.

GraphRAG is a Structural Requirement

Since the benchmark was published in 2023, FalkorDB has released a production-grade GraphRAG SDK that further improves retrieval alignment and LLM accuracy. In internal tests conducted in Q1 2025, average response accuracy for enterprise-style questions increased from the 56.2% reported in the original benchmark.

The most significant improvements occurred in KPI tracking and planning queries, where structural fidelity is critical. Internal evaluations show measurable improvements beyond the original 56.2% benchmark accuracy, especially in schema-dense enterprise use cases.

GraphRAG outperforms vector-based retrieval when schema precision matters. The KG-LM Accuracy Benchmark shows a 3.4x accuracy gain overall, and an infinite gain in schema-heavy categories where vector search fails entirely. These results validate using a graph database like FalkorDB as the retrieval backend in production LLM pipelines.

Why did vector RAG fail on Diffbot’s benchmark?

It failed schema-bound queries. Without entity alignment, LLMs couldn’t reason over KPIs, relationships, or planning logic.

What changed with FalkorDB’s GraphRAG SDK in 2025?

It added schema retrieval with low latency, pushing enterprise accuracy to 90%+

Can vector search ever match GraphRAG for structured data?

No. Vectors can’t model relationships. You can patch with rerankers, but you’ll keep losing speed, trust, and context.

Build fast and accurate GenAI apps with GraphRAG SDK at scale

FalkorDB offers an accurate, multi-tenant RAG solution based on our low-latency, scalable graph database technology. It’s ideal for highly technical teams that handle complex, interconnected data in real-time, resulting in fewer hallucinations and more accurate responses from LLMs.

References and citations

Build fast and accurate GenAI apps with GraphRAG-SDK at scale

FalkorDB offers an accurate, multi-tenant RAG solution based on our low-latency, scalable graph database technology. It’s ideal for highly technical teams that handle complex, interconnected data in real-time, resulting in fewer hallucinations and more accurate responses from LLMs.

Ultra-fast, multi-tenant graph database using sparse matrix representations and linear algebra, ideal for highly technical teams that handle complex data in real-time, resulting in fewer hallucinations and more accurate responses from LLMs.

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Avi Tel-Or

CTO at Intel Ignite Tel-Aviv

I enjoy using FalkorDB in the GraphRAG solution I'm working on.

As a developer, using graphs also gives me better visibility into what the algorithm does, when it fails, and how it could be improved. Doing that with similarity scoring is much less intuitive.

Dec 2, 2024

Ultra-fast, multi-tenant graph database using sparse matrix representations and linear algebra, ideal for highly technical teams that handle complex data in real-time, resulting in fewer hallucinations and more accurate responses from LLMs.

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