Ethereum vs Solana: Consensus in Action

60 DAY WEB3 JOURNEY (Day 15)

Previous: Layer 2 Solutions Deep-Dive: Optimistic vs ZK Rollups

Tomorrow: DAOs: Decentralized Organizations (Day 17)

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Introduction

Over the past two days, you've learned:

• Day 13: How consensus mechanisms work (PoW, PoS, DPoS)
• Day 14: How Layer 2s scale using rollups

Today, you'll see these concepts in action by comparing two of the largest blockchains: Ethereum and Solana.

They use completely different designs. Not because one team is smarter. But because they made different choices about what to optimize for.

Ethereum asks: "How do we maximize decentralization and security?"
Solana asks: "How do we maximize speed and throughput?"

Today, you'll understand why these choices matter and what each blockchain sacrificed to get what they wanted.

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The Design Philosophy: Two Different Bets

Ethereum's Philosophy

Goal: Build the most decentralized, censorship-resistant computer possible.

Strategy: If everyone can run a node, no one can control it.

Trade-off: This is slower and more expensive.

Solana's Philosophy

Goal: Build the fastest, most scalable blockchain possible.

Strategy: Accept some centralization now to prove the technology works.

Trade-off: This requires more trust in validators.

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Ethereum's Approach: PoS + Rollups

The Setup

Consensus: Proof of Stake (PoS)

• 500,000+ validators
• 32 ETH minimum to validate (~$100,000)
• Anyone can participate (high barrier, but decentralized)

Scaling: Layer 2 Rollups

• Process transactions off-chain
• Batch and settle on Layer 1
• Inherit Ethereum's security

How It Works

User sends transaction
→ L2 sequencer processes instantly
→ Bundled with 1,000s of others
→ Settled on Ethereum L1
→ Secured by 500,000+ validators

Result: Slow Layer 1, Fast Layer 2

Real Numbers

Ethereum Layer 1:

• 15 transactions per second
• $2–$10 per transaction
• 12-second block time
• Most secure (500,000+ validators)

Ethereum Layer 2 (Arbitrum/Optimism):

• 1,000–4,000 TPS
• $0.01–$0.10 per transaction
• 2-60 second confirmation
• Still inherits L1 security

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Why This Design?

Ethereum prioritizes:

1. Decentralization — Anyone with 32 ETH can validate
2. Security — 500,000+ validators make it nearly impossible to attack
3. Censorship-resistance — No single entity controls the network
4. Long-term vision — Build the foundation, scale later with L2s

Trade-offs

✅ Most decentralized major blockchain

✅ Proven security (billions locked)

✅ Massive developer ecosystem

✅ Clear roadmap (more rollups, sharding coming)

❌ Slow Layer 1 (15 TPS)

❌ Expensive to use directly

❌ Complex (users need to understand L1 vs L2)

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Solana's Approach: Proof of History + PoS

The Setup

Consensus: Proof of History (PoH) + Proof of Stake (PoS)

• ~430 validators
• 0.5 SOL minimum to validate (~$50)
• Low barrier, but fewer validators

Scaling: Single-layer design

• No rollups needed
• Process everything on Layer 1
• One unified network

How It Works: Proof of History

This is Solana's innovation.

Normal blockchains need validators to agree on the order of transactions:

Tx A happened
Tx B happened
Tx C happened

Validators: "Yep, that order is correct."

This takes time because everyone has to check.

Proof of History flips this:

Instead of asking "Did this transaction happen?", it proves "Did this transaction happen at this specific moment in time?"

Validator creates a cryptographic proof of timestamp
This proof can't be faked
Everyone trusts the timestamp, not consensus

Result: Order is already proven before consensus

Real Numbers

Solana Layer 1 (single chain):

• 65,000 TPS theoretical (currently ~400 TPS due to network limits)
• ~$0.00025 per transaction
• 400 millisecond block time
• Less decentralized (430 validators)

Why This Design?

Solana prioritizes:

1. Speed — Thousands of transactions per second
2. Scalability — Single chain handles everything
3. User experience — No need to understand L1 vs L2
4. Low cost — Transactions cost fractions of a cent

Trade-offs

✅ Extremely fast (65,000 TPS theoretical)

✅ Extremely cheap (~$0.00025 per tx)

✅ Simple user experience

✅ Growing developer ecosystem

❌ Less decentralized (430 validators vs 500,000)

❌ More network outages (2022 outage lasted 17 hours)

❌ Higher risk of censorship

❌ Novel tech (PoH is newer, less proven)

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Head-to-Head: Ethereum vs Solana

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Why Both Exist

You might ask: "If Solana is faster and cheaper, why use Ethereum?"

Because it's a tradeoff, not a ranking.

Use Ethereum If:

• You prioritize decentralization
• You want proven, battle-tested tech
• You need access to the largest ecosystem (most DeFi apps)
• You can afford to use L2s
• You're building infrastructure (validators, nodes)

Use Solana If:

• You prioritize speed and low cost
• You're doing high-frequency trading
• You're building real-time applications
• You're willing to accept less decentralization
• You're okay with occasional network issues

Reality:

Both will exist long-term because they solve different problems:

• Ethereum = "The most decentralized computer in the world"
• Solana = "The fastest blockchain for real-time apps"

It's like asking "Is a truck better than a car?" The answer is: it depends what you're doing.

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The Technical Differences Explained

Validator Requirements

Ethereum:

• 32 ETH (~$100,000)
• Run a node (commodity hardware)
• Result: 500,000+ validators worldwide

Solana:

• 0.5 SOL (~$50)
• Run a validator (requires serious hardware)
• Result: 430 validators (mostly institutions)

Impact: Ethereum is more decentralized; Solana is easier to become a validator in theory, but requires expensive infrastructure.

Transaction Finality

Ethereum L1:

• 12-second blocks
• Finality after ~15 minutes
• Rock solid

Ethereum L2:

• Instant confirmation (sequencer)
• 7-day finality (Optimistic) or instant (ZK)
• Still secure

Solana:

• 400-millisecond blocks
• Finality after ~13 seconds
• Fast but riskier

Security Model

Ethereum PoS:
Validators put 32 ETH at stake. If they cheat, they lose it all ("slashing"). Economic incentive prevents dishonesty.

Solana PoH:
Validators stake SOL, but PoH's cryptographic proof prevents them from cheating in the first place. Different approach, not necessarily weaker.

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What This Means for You

As a User:

• Want cheap, fast transactions? Use Solana or Ethereum L2s
• Want most security? Use Ethereum or Ethereum L2s
• Want both? Use Ethereum L2s (they give you both)

As a Developer:

• Want largest ecosystem? Build on Ethereum (most dApps, most tutorials, most funding)
• Want to build fast apps? Build on Solana (native speed, no L2 complexity)
• Want best of both worlds? Build on both (many projects do)

As an Investor:

• ETH: Bet on "decentralization and security win long-term"
• SOL: Bet on "speed and user experience win long-term"
• Both: Hedge your bets (different risk profiles)

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The Bigger Picture: Blockchain Tradeoffs

Ethereum and Solana represent two ends of a spectrum:

The fundamental insight: You can't maximize everything. Every blockchain makes tradeoffs.

Other blockchains make different bets:

• Bitcoin: Security > everything else
• Polygon: Decentralization + Speed (middle ground)
• Cardano: Academic rigor > speed
• Avalanche: Subnets (let each chain choose)

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Key Takeaways

• Ethereum chose decentralization and security using PoS + L2 rollups
• Solana chose speed and cost using Proof of History
• Both approaches work but have different tradeoffs
• They're not competitors — they solve different problems
• Neither is "better" — it depends what you need
• Both will coexist — like how TCP and UDP both exist in networking
• Future blockchains will make different bets — expect experimentation

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Questions to Explore

1. If Solana has 430 validators and Ethereum has 500,000, could Solana be 51% attacked more easily? Why or why not?
2. Why would someone choose Ethereum's high cost when Solana is cheaper? What's the value-add?
3. Could Solana add more validators to become more decentralized? What would happen?
4. Is Proof of History fundamentally more efficient than PoS, or does it just make different tradeoffs?
5. Could a blockchain be fast AND decentralized? What would it need to achieve both?

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Series Navigation

60-Day Web3 Journey:

• Day 14: Consensus Mechanisms Explained
• Day 15: Layer 2 Solutions Deep-Dive
• Day 16: Ethereum vs Solana (Current)
• Day 17: DAOs: Decentralized Organizations (Coming tomorrow)

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What's Next?

Tomorrow (Day 17): DAOs: Decentralized Organizations — How communities can organize without a CEO or board of directors.

You'll learn:

What DAOs actually are (beyond the hype)
How voting works in decentralized governance
Real-world examples (Uniswap DAO, MakerDAO, etc.)
How to participate in a DAO

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Resources & Further Reading

Official Documentation:

Ethereum: https://ethereum.org/ — Official hub with guides, documentation, and staking information

Solana: https://solana.com/ — Official Solana homepage and ecosystem overview

Solana Docs: https://docs.solana.com/ — Official Solana documentation and Proof of History explanation

Comparison & Metrics:

L2Beat: https://l2beat.com/ — Compare Ethereum Layer 2 solutions (TVL, fees, security)

Token Terminal: https://tokenterminal.com/ — Blockchain metrics and analytics dashboard

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Community:

Web3 for Humans Telegram: https://t.me/Web3ForHumans — Join daily Web3 discussions

Follow on Twitter: https://x.com/RibsModi — Stay updated with new content