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Lochan VISNU CHELUVAIAHGAL
Lochan VISNU CHELUVAIAHGAL

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Tigergraph Hackathon

🚀 Beating the Token Explosion: How GraphRAG Outperforms Vector Search in Medical AI

As Large Language Models (LLMs) scale across industries, developers are hitting a massive wall: the token explosion. Shoving massive document dumps into an LLM's context window isn't just slow—it is incredibly expensive. In domains like healthcare, where precision is everything, hallucinating because the model lost track of complex relationships isn't just an error; it's a critical failure.

For the 🏆 TigerGraph GraphRAG Inference Hackathon, I wanted to prove that graphs make LLM inference faster, cheaper, and fundamentally smarter. The goal wasn't just to build a pipeline, but to benchmark token reduction while rigorously maintaining answer accuracy through a custom-built, interactive UI.

Here is a technical breakdown of how I built an interactive GraphRAG benchmark using Python and tkinter, the three pipelines I compared, and the data that proves why graphs are the future of retrieval.


🏥 The Problem and The Medical Dataset

Building robust architecture for healthcare applications requires absolute precision. That is why I chose a dense Medical Dataset—mapping specific diseases and their overlapping symptoms—for this hackathon.

Medical data is inherently a graph. A symptom links to multiple possible diseases, and a disease links to specific treatments. Standard vector search struggles to connect these dots safely. We needed a knowledge graph.


🖥️ System Architecture & The Tkinter Dashboard

To make the comparison tangible and user-friendly, I didn't want a clunky command-line script. Instead, I built a lightweight, interactive GUI using Python's tkinter library.

This tkinter dashboard acts as our command center. You enter a single patient symptom query, and the GUI simultaneously routes it through all three pipelines, displaying the responses side-by-side along with real-time metrics.

[DRAG AND DROP YOUR ARCHITECTURE DIAGRAM IMAGE HERE]
(Caption: The data flow of our GraphRAG inference system, controlled via a custom tkinter GUI.)


🧠 The Three Inference Pipelines: A Medical Case Study

To truly measure the impact, the tkinter app evaluates three side-by-side pipelines answering the exact same symptom-based queries. Let's look at how they handle a multi-hop query like: "What diseases share the symptoms of chronic migraines, acute nausea, and severe vertigo?"

❌ Pipeline 1: LLM-Only (The Baseline)

  • How it works: A prompt goes in, and an output comes out. Zero external retrieval.
  • The Medical Result: The LLM relies entirely on its pre-trained weights. It might generate generic advice or hallucinate a completely unrelated disease. In healthcare AI, this worst-case baseline is highly risky.

⚠️ Pipeline 2: Basic RAG (Vector + LLM)

  • How it works: The current industry standard. Vector embeddings retrieve the most mathematically similar text chunks regarding the listed symptoms, dumping them into the context window.
  • The Medical Result: It pulls a massive, noisy context dump of symptom descriptions. The LLM has to read through thousands of tokens to try and find the overlap. It frequently misses crucial relationship data because vector search treats text as independent chunks, not connected facts.

✅ Pipeline 3: GraphRAG (Graph + LLM)

  • How it works: Built using the TigerGraph GraphRAG repository. We modeled the data as interconnected entities (Disease and Symptom) and relationships (HAS_SYMPTOM).
  • The Medical Result: TigerGraph performs true multi-hop reasoning. It identifies the symptoms, traces the graph edges to find diseases that intersect with all of them, and actively filters out noise. The LLM receives a clean, highly structured, and filtered prompt.

📊 Evaluating the Metrics: The Comparison Dashboard

The heart of this project is the interactive tkinter comparison dashboard. Here is how the performance metrics stacked up during testing:

Metric Pipeline 1 (LLM-Only) Pipeline 2 (Basic RAG) Pipeline 3 (GraphRAG)
Tokens Used Baseline (Prompt only) Extremely High (Massive context dump) Significantly Reduced
Cost Per Query Lowest Highest Optimized
Response Latency Fast Slowest (Due to reading massive chunks) Balanced / Efficient
Multi-Hop Reasoning Fails completely Fails frequently Excels

[DRAG AND DROP YOUR TKINTER DASHBOARD / COMPARISON IMAGE HERE]


🎯 Ensuring Answer Accuracy (The Hugging Face Evaluation)

Cutting tokens is useless if the answer quality drops—especially with medical data. To prove Pipeline 3's superiority, every response was rigorously evaluated using two complementary Hugging Face approaches:

  1. LLM-as-a-Judge: A hosted Hugging Face model graded each answer on a PASS/FAIL basis, targeting a pass rate of ≥ 90%.
  2. BERTScore: We measured the semantic similarity of the generated response against the ground-truth correct answer, aiming for an F1 rescaled score of ≥ 0.55.

Through iterative parameter tuning, the GraphRAG pipeline consistently hit these high-accuracy thresholds while utilizing a fraction of the tokens required by Basic RAG.

[DRAG AND DROP YOUR BENCHMARK REPORT IMAGE HERE]


💡 The Verdict

The numbers tell the story. By feeding the LLM structured graph relationships instead of raw vector chunks, TigerGraph extracts exactly what is needed for complex, symptom-to-disease routing. This means optimized API costs, faster generation times, and highly accurate, hallucination-resistant answers. See the Code & Demo:

  • 💻 Source Code: [INSERT GITHUB REPO LINK]
  • 🎥 Demo Video: Watch the full system walkthrough[INSERT LINK]

A huge thank you to the TigerGraph team for providing the open-source repo, the Savanna environment, and the opportunity to tackle this industry-wide problem.

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