Comparing blockchains and their trade-offs
About 2453 wordsAbout 8 min
Part 1 sorted blockchains by who is allowed in. Today sorts the public ones by what they optimise for.
There are thousands of chains and you will never evaluate them one at a time. What you can do is learn the handful of dimensions they all vary along.
The conclusion, stated up front
Different blockchains make different design choices. None of them is strictly best. A chain advertising a number without naming its cost is marketing, not engineering.
Learning objectives
- Name the dimensions along which blockchain designs differ
- Explain the trade-off between decentralisation and throughput
- Compare two chains on three dimensions and say what each gave up
- Recognise when a performance claim has quietly omitted its cost
Core
Start with four questions
Before comparing detailed specifications, use four simple questions:
- How fast and affordable is it for the thing we want to do?
- Who can realistically help secure or validate it?
- What can developers build on it?
- What did the design give up to get those benefits?
These questions provide a first lens. The seven dimensions below make the lens more complete without turning it into a memorisation exercise.
How to read these examples
Start with three familiar shapes:
- Bitcoin: conservative and narrow, prioritising security and predictability.
- Ethereum: programmable, with a broad ecosystem and a strong focus on decentralisation; it scales through both its base layer and Layer 2s.
- Solana: high performance, with higher hardware requirements and different trade-offs.
These are not complete verdicts. Read Bitcoin, Ethereum and Solana as the main contrasting shapes; Cosmos and Avalanche broaden the design space by showing other ways to organise chains and security. You are not expected to memorise chain specifications, block times, throughput numbers, consensus names or validator requirements. Use the comparisons to practise asking better questions.
The central tension
Most of what follows reduces to one pressure.
You will hear this framed as the blockchain trilemma — decentralisation, security, scalability, pick two.
Treat the trilemma as a rule of thumb, not a law
Enormous engineering effort goes into softening it, and Part 5 covers the most successful attempt so far. But the pressure is real, and a chain claiming to have escaped it entirely has usually just moved the cost somewhere you were not looking.
The seven dimensions
You are not expected to memorise the specifications. Use the dimensions to ask better questions and explain what a chain gains and gives up.
| Dimension | The question |
|---|---|
| Decentralisation | How many independent participants, how spread out? |
| Finality | How long until a transaction is genuinely settled? |
| Throughput | How many transactions per second? |
| Security participation | What does it take to help secure the network? |
| Execution model | What can the chain compute, and how? |
| Ecosystem | What already exists — tools, users, applications? |
| Design trade-off | What was deliberately given up, and for what? |
That last row is the one beginners skip and the one that tells you the most.
Five representative chains
Chosen because they made genuinely different choices — not because they are the five best.
Figures are approximate and directional
Real throughput depends on transaction type and network conditions, and advertised maximums are almost never sustained. Use these to compare shapes, not to quote numbers.
Question: Can strangers maintain scarce digital money without one trusted ledger operator?
Bitcoin answers with a deliberately narrow ledger and Proof of Work. That choice prioritises simplicity, predictability and security; it gives up throughput and general-purpose programmability.
| Aspect | Details |
|---|---|
| Consensus | Proof of Work |
| Finality | Probabilistic; roughly an hour is commonly used for high confidence |
| Throughput | Very low — a handful per second |
| Security participation | Mining: specialised hardware + electricity |
| Execution | Deliberately limited scripting. Not general-purpose |
| Trade-off | Gave up nearly everything for security, simplicity and predictability |
Bitcoin's limitations are not failures to fix. They are the design. Less functionality means less to attack and less to argue about. It has kept a deliberately narrow and conservative design since 2009.
Question: What if a blockchain should maintain digital money and also run general-purpose rules and applications?
Bitcoin showed that a blockchain could maintain digital money. Ethereum broadened that idea into programmable shared state through smart contracts and the EVM. It gains flexibility and a broad ecosystem, while accepting lower base-layer throughput and scaling through Layer 2s.
| Aspect | Details |
|---|---|
| Consensus | Proof of Stake |
| Finality | Explicit, about 15 minutes |
| Throughput | Lower at the base layer than high-throughput chains; capacity is increasing |
| Security participation | Solo validator: 32 ETH + suitable hardware. Pools let smaller holders participate economically without running their own validator |
| Execution | The EVM. General-purpose smart contracts |
| Trade-off | Accepted low base-layer throughput to keep validation cheap enough for ordinary hardware — then scaled via Layer 2 |
Ethereum historically kept L1 capacity conservative so that validating the chain remained accessible, while scaling heavily through Layer 2s. Today it is scaling both: gradually increasing L1 capacity while continuing to expand L2 capacity.
Question: What if public blockchain applications need faster responses, low fees and much more activity?
Solana prioritises that user-facing performance by accepting higher hardware, bandwidth and stake requirements. It still uses stake-based consensus; Proof of History adds a cryptographic clock and ordering signal that helps participants agree on when events happened, but it does not replace Proof of Stake.
| Aspect | Details |
|---|---|
| Consensus | Proof of Stake; Proof of History helps provide a shared clock and ordering signal |
| Finality | Fast — seconds |
| Throughput | High — thousands per second |
| Security participation | Substantial — comparatively high-spec hardware, bandwidth and stake/economic resources |
| Execution | Parallel: non-conflicting transactions run simultaneously |
| Trade-off | Accepted higher validator costs, and historically some stability incidents, for speed and very low fees |
Solana genuinely delivers the performance. The honest accounting is that it costs real money to run a validator, which concentrates who can — and the network has had outages that Ethereum and Bitcoin have not.
Question: What if applications or communities want their own sovereign blockchains, but still want those chains to communicate?
Cosmos answers with many chains instead of one shared execution environment. A standard communication protocol between connected chains, Inter-Blockchain Communication (IBC), helps them exchange messages while each chain keeps its own rules and validators.
Think of Cosmos less like one giant city and more like a federation of independent countries: each chain can keep its own rules and validators, while IBC gives compatible chains a common way to communicate. The analogy is about sovereignty and communication, not literal governments.
| Aspect | Details |
|---|---|
| Consensus | Proof of Stake; CometBFT is one software family for validator voting |
| Finality | Deterministic once a block is committed |
| Throughput | High per chain |
| Security participation | Depends on the chain's validator set or shared-security model |
| Execution | Each chain builds its own; connected through IBC, a standard communication protocol |
| Trade-off | Many chains choose sovereignty and their own validator set; some use shared-security models instead |
Many Cosmos chains run their own validator sets, trading shared security for sovereignty. Some can also use shared-security models such as Interchain Security.
Question: What if an application wants its own blockchain because it needs different fees, throughput, validator rules, access controls or token economics?
Avalanche L1s provide configurable sovereign networks, which can be application-specific when a project needs that level of control. This can give a project more control over fees, throughput, validator rules, access controls or token economics and isolate its workload, but the network must still define and fund its own security and validator system.
Deploying a smart contract on a general-purpose chain is like renting a shop in someone else's city: you can run your business, but you still follow the city's infrastructure rules. A dedicated/application-specific chain can be closer to building your own campus — more control, but more responsibility for the infrastructure and security. This explains why a project might want a dedicated chain; it is not a definition of every Avalanche L1. The analogy stops there: an Avalanche L1 still needs a real network and validator configuration, not just a campus plan.
An Avalanche L1 is a configurable sovereign network with its own validator configuration. Some are application-specific; these networks were formerly commonly called Subnets.
| Aspect | Details |
|---|---|
| Consensus | Avalanche consensus — repeated randomised sampling |
| Finality | Fast — around a second |
| Throughput | High |
| Security participation | Depends on the particular Avalanche L1's validator configuration |
| Execution | Multiple chains; EVM-compatible option; configurable Avalanche L1s |
| Trade-off | Optimised for configurable networks over one shared environment; some are application-specific |
Side by side
| Dimension | Bitcoin | Ethereum | Solana | Cosmos | Avalanche |
|---|---|---|---|---|---|
| Operator participation | Open under protocol rules | Broad participation is the goal; hardware, stake and client/operator spread still matter | Higher-spec hardware and stake can narrow participation | Depends on each chain and security model | Depends on each Avalanche L1 configuration |
| Finality | Probabilistic; confidence grows | Explicit; roughly minutes | Seconds | Deterministic after commit | Fast; depends on configuration |
| Throughput | Very low | Low (base) | High | High | High |
| Security participation | Mining hardware + power | Solo: 32 ETH + hardware; pools are economic participation | Higher-spec hardware + stake | Per-chain or shared-security model | Per-L1 validator configuration |
| Execution | Limited | EVM | Parallel | Per chain | Configurable |
Read the columns downward, not the rows across
These are rough qualitative descriptions of particular dimensions, not one objective decentralisation score. The point is not that anyone set out to choose "moderate decentralisation". Solana's emphasis on speed makes the validator trade-off especially visible.
Landscape
- Blockchain trilemma — a reminder that decentralisation, security and scalability pull in different directions. A chain that improves one may accept a trade-off in another; it is a question, not a proof
- BFT consensus — ways for a set of validators to reach a clear decision quickly, even if some fail or behave badly. It is a family of approaches, not one single protocol
- Parallel execution — running independent transactions at the same time. It can process more transactions, but the chain must first know that the transactions do not conflict
- IBC — a Cosmos messaging standard that lets connected chains send verified messages. It does not make them one ledger, and each connection still has assumptions to check
- Avalanche L1 / appchain — Avalanche L1s are configurable sovereign networks; some are designed as appchains for a particular application or ecosystem. Appchain describes purpose, not automatically the network's security model. Part 5
- EVM-compatible — a network that can run Ethereum-style contracts. Close compatibility lets tools and code be reused, but differences can still matter
- Shared vs sovereign security — whether a chain borrows security from another network or runs its own security. Borrowing reduces the chain's own burden; sovereignty gives control but leaves the chain responsible for its security budget
- Client diversity — having more than one independent software implementation of a network. It can reduce the chance that one software bug affects everyone
Worked example
"Which chain should a payments app for small merchants in Southeast Asia use?"
Do not start from a favourite. Start from what the application needs.
| Requirement | Consequence |
|---|---|
| Fast user-facing confirmation while the customer waits | Needs fast inclusion; the app may accept that stronger protocol finality takes longer, depending on the value and use case |
| Fees well under a cent | Rules out congested base layers |
| Stablecoin support | Needs a real ecosystem, not just a chain |
| Merchants cannot lose funds to outages | Uptime is a hard requirement |
The candidates, honestly:
| Candidate | Verdict |
|---|---|
| Bitcoin | No. Roughly an hour is commonly used for high confidence, and Bitcoin has no native stablecoin support |
| Ethereum L1 | No for this target. Fees are usually too high, and the application would need to decide whether its stronger finality delay is acceptable |
| Solana | Plausible. Fast, cheap, strong stablecoin usage. Weigh the outage history |
| An Ethereum L2 | Plausible. Cheap and fast, with Ethereum behind it |
| A dedicated Cosmos/appchain design | Usually overkill unless the application genuinely needs chain-level control. If it does, the project also takes on validator, security and infrastructure responsibility |
There is no single right answer — that is the exercise
What you should be able to say is: "We chose X. It gives us speed and low fees. What we gave up is Y, and here is why that is acceptable for this use case."
Someone who says "we chose X because it is the best chain" has not understood this material.
Further exploration — optional, not assessed
- Solana docs · CometBFT docs · Avalanche docs — primary sources for three of the five
- Bitcoin whitepaper — nine pages, and the origin of the constraints Bitcoin still honours
- Modular blockchains and data availability layers — the current frontier of this argument
Sources and attribution
- ethereum.org — Consensus mechanisms — Reuse (CC BY 4.0), adapted
- Bitcoin whitepaper — Link, referenced only
- Solana documentation — Link, referenced only
- CometBFT documentation — Link, referenced only
- Avalanche documentation — Link, referenced only
- Avalanche L1s documentation — Link, referenced for the application-specific network example
Named networks are illustrative examples, not recommendations. Performance figures are approximate and change; verify against primary sources.
Changelog
ff0f4-feat(academy): finalize Foundation learning experienceon57062-docs(foundation): strengthen beginner concept-to-reality progressionona931f-docs(foundation): finalize beginner learning path and handbook UXon2d4b4-docs(curriculum): finalize Week 0-2 Foundation revisiononaed71-Bootstrap Blockchain@NTU Academy Handbookon