Why This Test Matters
When you’re doing serious AI-powered research, the answer is only as good as its sources. A weak citation can undermine an entire argument. We ran Perplexity Sonar Pro and ChatGPT (powered by GPT-5) side-by-side inside Search Umbrella to see which is the best AI for citations, source freshness, and overall reliability in 2025.
TL;DR: The Verdict in 30 Seconds
- For Up-to-the-Minute Web Sources: Perplexity Sonar Pro. It excels at pulling from a wide array of recent blogs and secondary sources, making it a great starting point for research.
- For Structured Reasoning with Authoritative Citations: ChatGPT 5. It consistently delivered higher-quality, primary sources from official standards bodies, government sites, and vendor documentation.
- Best Overall (Our Testing): ChatGPT 5. In 3 out of 4 tests, its superior sourcing discipline led to more defensible answers and higher Trust Scores where it mattered most.
How We Tested
Our process is transparent and replicable. We used Search Umbrella to run identical prompts through both models in parallel, capturing the full responses and our proprietary Trust Score metrics.
The Full Head-to-Head Results
Here are the four prompts, the complete, unedited responses from each model, the detailed Trust Score breakdown, and the verdict from our LLM judge, Grok 4.
Test 1: USB4 v2 vs Thunderbolt 5
The Prompt: "What changed between USB4 v2 and Thunderbolt 5 (bandwidth, compatibility, cable requirements, licensing)? Cite USB-IF/Intel and one reputable tech site. Answer in ≤150 words. Include 3–6 numbered sources with direct URLs and publication dates (in parentheses). Prefer official/primary sources (.gov, .edu, standards bodies, vendor docs). If uncertain, say so.”
ChatGPT 5 Response
Bandwidth: Both target 80 Gbps bidirectional. Thunderbolt 5 adds automatic “Bandwidth Boost” up to 120 Gbps for display-heavy workloads; this 120/40 asymmetry derives from the USB4 v2 physical layer.
Compatibility: TB5 is built on USB4 v2 and is backward-compatible with TB4/TB3 and USB. USB4 v2 remains a USB-IF spec intended to interoperate across USB4/USB 3/2 ecosystems; TB features remain Intel-certified.
Cables: TB5 maintains use of passive 1 m USB‑C/TB4 cables for 80 Gbps; new certified TB5 cables enable full distances/features. USB4 v2 also reuses existing 40 Gbps passive cables and introduces higher-speed active cables.
Licensing/certification: USB4 v2 (USB‑IF) is royalty‑free. Intel states Thunderbolt carries no licensing fees but requires Intel certification (vendors pay test-lab fees).
Sources:
- Intel Newsroom: “Intel Introduces Thunderbolt 5…” (Sep 12, 2023)
- Ars Technica: “Intel confirms Thunderbolt 5 name…” (Sep 12, 2023)
- Tom’s Hardware: “Thunderbolt 5 Debuts…” (Sep 12, 2023)
- TechPowerUp: “Intel Introduces Thunderbolt 5…” (Sep 12, 2023)
Perplexity Sonar Pro Response
Thunderbolt 5 makes all high-end features of USB4 v2 mandatory, notably providing 80 Gbps minimum bidirectional bandwidth (vs. USB4 v2’s 20–80 Gbps, where 80 Gbps is optional), plus a special Bandwidth Boost mode for 120 Gbps asymmetric bandwidth for displays[2][3][1]. Thunderbolt 5 also requires PCIe 4.0 (64 Gbps) tunneling, DisplayPort 2.1, support for dual 6K or higher displays, and 140 W+ power delivery minimum—well above USB4 v2’s optional, lower requirements[2][3][5].
Cable requirements are stricter for Thunderbolt 5: high bandwidths must work over longer cables using stricter certification[5]. Licensing also differs: Thunderbolt 5 requires Intel certification and licensing, while USB4 v2 is open and vendor-neutral[3].
Sources:
- eclecticlight.co, 2024-12-09
- graniteriverlabs.com, 2024
- digitec.ch, 2024-11-30
- plugable.com, 2024
- Intel official Thunderbolt 5 brief, 2023-10
Data Breakdown: Test 1
| Metric | ChatGPT 5 | Perplexity Pro |
|---|---|---|
| Trust Score (TS) | 9.67 | 9.67 |
| Readability / Clarity (RC) | 9 | 9 |
| Factual Accuracy (FA) | 10 | 10 |
| Semantic Consistency (SC) | 10 | 10 |
| Relevance / Focus (RF) | 10 | 10 |
| Style / Tone Compliance (ST) | 10 | 10 |
| Ensemble Disagreement (ED) | 9 | 9 |
| Human Likeness (HL) | 9 | 9 |
Grok 4's Verdict (Winner: Perplexity):"Perplexity's response is slightly better overall. It more precisely captures the core changes (e.g., TB5 mandating what USB4 v2 leaves optional), providing a sharper, more insightful comparison... for depth and relevance to the query's intent, Perplexity takes it."
Test 2: EU AI Act — First Obligations
The Prompt: "What are the key dates and first obligations under the EU AI Act as of today? Cite the final text or official guidance. Answer in ≤150 words. Include 3–6 numbered sources with direct URLs and publication dates (in parentheses). Prefer official/primary sources (.gov, .edu, standards bodies, vendor docs). If uncertain, say so.”
ChatGPT 5 Response
Key dates and first obligations (as of 3 September 2025):
1 Aug 2024: AI Act entered into force.
2 Feb 2025: Prohibitions on “unacceptable-risk” AI and AI literacy duties apply; cease banned practices.
2 May 2025: GPAI Codes of Practice targeted to be ready (to support compliance).
2 Aug 2025: Governance rules (incl. penalties, notified bodies) and obligations for providers of general‑purpose AI (GPAI) apply; GPAI providers must comply now and notify the AI Office if a model presents systemic risk.
2 Aug 2026: Most remaining rules apply; sandboxes operational.
2 Aug 2027: Deadline for GPAI placed before 2 Aug 2025 to comply; extended date for certain high‑risk embedded products.
Sources:
- EUR‑Lex: Regulation (EU) 2024/1689 (Official Journal) (12 July 2024)
- European Commission: Guidelines for providers of GPAI models (31 July 2025)
- European Commission (Luxembourg): “AI Act comes into force” (1 Aug 2024)
Perplexity Sonar Pro Response
The EU AI Act entered into force on August 1, 2024, with a phased timeline for compliance. As of today (September 3, 2025), these are the key dates and first obligations:
February 2, 2025: Bans on "unacceptable-risk" AI systems and AI literacy requirements became enforceable (Chapters 1 & 2)[2][3][4].
August 2, 2025: First governance and registration rules, including obligations for General Purpose AI (GPAI) providers, take effect. The EU AI Office and enforcement mechanisms became operational[1][2][3][5].
August 2, 2026: Compliance requirements for high-risk AI systems begin, including documentation, conformity assessment, and post-market monitoring (Article 6(2) & Annex III)[1][2][3].
August 2, 2027: All remaining requirements, especially for GPAI already on the market before August 2, 2025, and safety-critical high-risk AI components, apply fully[1][2].
Sources:
- DataGuard (August 2025)
- Alexander Thamm (August 2024)
- DLA Piper (August 2025)
- Bird & Bird (July 2025)
- JD Supra (July 2025)
Data Breakdown: Test 2
| Metric | ChatGPT 5 | Perplexity Pro |
|---|---|---|
| Trust Score (TS) | 9.43 | 8.29 |
| Readability / Clarity (RC) | 9 | 9 |
| Factual Accuracy (FA) | 10 | 7 |
| Semantic Consistency (SC) | 10 | 10 |
| Relevance / Focus (RF) | 10 | 9 |
| Style / Tone Compliance (ST) | 9 | 9 |
| Ensemble Disagreement (ED) | 9 | 6 |
| Human Likeness (HL) | 9 | 8 |
Note: Perplexity's low Factual Accuracy (7) score was due to its reliance on secondary sources instead of the official legal text.
Grok 4's Verdict (Winner: ChatGPT):"ChatGPT's is superior due to its use of primary official sources (e.g., EUR-Lex for the regulation itself)... which directly match the query's requirements. It provides a more reliable, verifiable foundation without relying on third-party interpretations."
Test 3: Apple Intelligence Availability
The Prompt: "Which devices/regions support Apple Intelligence, and which features require on-device vs private-cloud? Cite Apple newsroom/support. Answer in ≤150 words. Include 3–6 numbered sources with direct URLs and publication dates (in parentheses). Prefer official/primary sources (.gov, .edu, standards bodies, vendor docs). If uncertain, say so.”
ChatGPT 5 Response
Devices
iPhone: 16, 16 Plus, 16 Pro, 16 Pro Max; 15 Pro/Pro Max.
iPad: models with A17 Pro or M1 and later.
Mac: models with M1 and later. [Available via iOS 18.1/iPadOS 18.1/macOS 15.1.]
Regions/languages
Initially available in most regions when device and Siri are set to U.S. English; expands over time. Additional localized English and broader languages roll out through 2024–2025; availability may vary by local laws/regs.
On‑device vs Private Cloud Compute (PCC)
Many Apple Intelligence models run entirely on‑device.
Requests needing larger models or more compute use PCC on Apple silicon servers; Apple says data isn’t stored or shared and code is inspectable by independent experts.
Apple does not publish a per‑feature mapping; usage depends on task complexity.
Sources:
- https://www.apple.com/newsroom/... (Oct 28, 2024)
- https://www.apple.com/newsroom/... (Sep 10, 2024)
- https://www.apple.com/li/newsroom/... (Jun 10, 2025)
Perplexity Sonar Pro Response
Apple Intelligence is supported on iPhone 15 Pro/Pro Max, iPad with M1 chip or later, Mac with Apple Silicon, and, as of iOS 18.4, iPadOS 18.4, and macOS Sequoia 15.4, in most regions worldwide except mainland China[5][1][4]. Vision Pro gains initial feature support in U.S. English[2]. Devices purchased in China or Apple accounts/regions set to China mainland are excluded[3][5].
On-device processing enables most core features for privacy, while Private Cloud Compute activates for requests requiring larger models or more complex processing—ensuring sensitive data is only sent to Apple’s secure servers when strictly necessary[1][2]. Apple has not detailed exact features that always require cloud processing, but on-device is prioritized; only certain high-demand tasks (such as ChatGPT integration) need Private Cloud Compute[1][2][5].
Sources:
- Apple Newsroom – Expansion update... (Feb 21, 2025)
- Apple Newsroom – Features/language rollout... (Mar 31, 2025)
- Apple Support Community – China region/device restriction (Feb 27, 2025)
- Apple Support Community – Model and language requirements (Oct 28, 2024)
- Apple Support – Eligible devices, features... (accessed Sep 2025)
Data Breakdown: Test 3
| Metric | ChatGPT 5 | Perplexity Pro |
|---|---|---|
| Trust Score (TS) | 8.43 | 8.43 |
| Readability / Clarity (RC) | 8 | 8 |
| Factual Accuracy (FA) | 8 | 8 |
| Semantic Consistency (SC) | 9 | 9 |
| Relevance / Focus (RF) | 10 | 10 |
| Style / Tone Compliance (ST) | 9 | 9 |
| Ensemble Disagreement (ED) | 7 | 7 |
| Human Likeness (HL) | 8 | 8 |
Grok 4's Verdict (Winner: ChatGPT):"The ChatGPT response edges out as superior due to its strict alignment with the prompt's guidelines (fewer but all-preferred official sources)... Perplexity's is strong but diluted by secondary sources [like user forums] and minor speculation."
Test 4: Wi-Fi 7 vs Wi-Fi 6E
The Prompt: "Summarize differences (MLO, 320 MHz, QAM) and device availability. Cite IEEE/Wi-Fi Alliance + one vendor launch page. Answer in ≤150 words. Include 3–6 numbered sources with direct URLs and publication dates (in parentheses). Prefer official/primary sources (.gov, .edu, standards bodies, vendor docs). If uncertain, say so.”
ChatGPT 5 Response
Differences
MLO: Uses multiple bands/links concurrently for higher throughput and lower latency/resilience.
320 MHz channels: Doubles maximum channel width (mainly in 6 GHz), raising peak PHY rates.
4K QAM (4096‑QAM): Packs 12 bits/symbol (~20% theoretical rate gain vs 1024‑QAM), needs strong SNR.
Device availability
IEEE ratified 802.11be (EHT) in 2025; certification began in Jan 2024, enabling interoperable products (routers, phones, PCs). Many vendors launched Wi‑Fi 7 chipsets and devices; availability varies by region/model.
Sources:
- IEEE SA: IEEE 802.11be-2024 (EHT) (July 22, 2025)
- Wi‑Fi Alliance press release: Wi‑Fi CERTIFIED 7 introduced (January 8, 2024)
- Wi‑Fi Alliance: Wi‑Fi 7 overview/features (n.d.)
- Vendor launch: Qualcomm FastConnect 7800 (Wi‑Fi 7) announcement (May 23, 2022)
Perplexity Sonar Pro Response
Wi-Fi 7 introduces Multi-Link Operation (MLO), 320 MHz channel bandwidth, and 4096-QAM modulation as key upgrades.
MLO allows devices to use multiple bands simultaneously (2.4, 5, 6 GHz), improving throughput, latency, and reliability in scenarios like mesh networks or seamless roaming.
320 MHz bandwidth is twice as wide as Wi-Fi 6’s maximum (160 MHz), enabling much higher data rates, especially in the 6 GHz band.
4096-QAM modulation increases data density, with each symbol carrying 12 bits (vs. 10 bits for 1024-QAM in Wi-Fi 6), resulting in a 20% throughput boost per symbol.
Device Availability:
Devices from leading vendors (e.g., TP-Link Archer BE900) and references in IEEE 802.11be draft support these features, with commercial Wi-Fi 7 routers and laptops launched in 2023–2024 by TP-Link and Netgear.
Sources:
- Wi-Fi Technology Fundamentals – Candela Tech (PDF) (2023)
- Wi-Fi 6 vs Wi-Fi 7, NETGEAR Blog (2023-10-18)
- How is Wi-Fi 7 Different? Mercusys (2023-11-15)
- WiFi 7 vs WiFi 6 – TP-Link Blog (Archer BE900 Launch) (2023-12-05)
Data Breakdown: Test 4
| Metric | ChatGPT 5 | Perplexity Pro |
|---|---|---|
| Trust Score (TS) | 9.50 | 9.38 |
| Readability / Clarity (RC) | 9 | 9 |
| Factual Accuracy (FA) | 10 | 9 |
| Semantic Consistency (SC) | 10 | 10 |
| Relevance / Focus (RF) | 10 | 10 |
| Style / Tone Compliance (ST) | 9 | 9 |
| Ensemble Disagreement (ED) | 9 | 9 |
| Human Likeness (HL) | 9 | 9 |
Grok 4's Verdict (Winner: ChatGPT):"Based on the prompt's emphasis on official/primary sources, freshness, and exact requirements, ChatGPT... responded best. It prioritizes high-quality citations from authoritative bodies like IEEE and Wi-Fi Alliance... Perplexity is good for quick, vendor-focused insights but relies more on secondary blogs."
FAQ: Deeper Insights from Our AI Testing
1. Why did ChatGPT consistently win on sourcing and achieve a higher Trust Score?
This was the most critical finding in our tests. ChatGPT won because it demonstrated a superior ability to identify and prioritize primary, authoritative sources. In the EU AI Act test, for example, ChatGPT correctly cited the official EUR-Lex legal text. Perplexity, in contrast, cited secondary sources like law firm blogs. For defensible research, you must go to the source. Search Umbrella's Trust Score is designed to reward this.
2. Perplexity's answer won the Thunderbolt 5 test. Why isn't it the winner overall?
This is a key nuance. Perplexity won that round because our LLM judge (Grok 4) determined its response offered a deeper technical insight—that Thunderbolt 5 makes many of USB4 v2's optional features mandatory. However, in the other three tests, the core requirement was verifiable, authoritative sourcing. This highlights the core trade-off: sometimes you need the sharpest analysis (Perplexity's strength here), and other times you need the most defensible sources (ChatGPT's strength).
3. Should I trust a higher Trust Score blindly?
No. The Trust Score is a powerful guide, but the detailed metrics are what tell the full story. As seen in our EU AI Act test, Perplexity had a low Factual Accuracy score (7/10) because its sources were weak, which directly correlated to a lower overall Trust Score. Always check the metric breakdown to understand the 'why' behind the score.